Triang Relations



The first assumption in a relationship described as a Love Triangle is that someone has got to go. There is a lot of good drama/comedy in that little conundrum.

Even if the writer chooses to challenge that assumption, there will be some pretty tricky footwork required to make it all come out to a resolution.

Here are the possible triangles. Put one to work.

These are all point-in-time snapshots. Could be the situation at the beginning or it could be after some story has gone by. These are often used to construct all sorts of Love Polyhedra. Also, not all Triang Relations fit into these classifications (for example, a scenario where A and B love each other, A and C love each other, and B and C like but don't love each other is neither Type 7 nor Type 8).

1. Alice wants both Bob and Charlie, but cannot decide which. Both are unrequited or their wishes are unimportant.
This is the classic Betty and Veronica trope. See that page for details and examples.

2. Alice wants Bob, Bob wants Claire, and Claire wants Alice.
Sometimes referred to as a Bizarre Love Triangle, after the New Order song.

Anime and Manga

 * The manga Girl X Girl X Boy has one of these triangles most of the way through.
 * Natalia (Belarus), Ivan (Russia) and Toris (Lithuania) from Axis Powers Hetalia. With a twist: Belarus and Russia are siblings. Completely, utterly, and hilariously insane siblings. Poor Lithuania...
 * Juri, Shiori and Ruka in Revolutionary Girl Utena.

Film

 * The 1994 movie Threesome uses this setup with two men and a woman.
 * She's The Man with the crossover setup. Viola becomes Sebastian, and falls in love with Duke. Duke then falls in love with Olivia, and Olivia falls in love with Sebastian (really Viola). There's a bit more to it than that - the real Sebastian, Viola's brother, is dating Monique so Viola hates Olivia, but Olivia goes out with Duke to make Viola jealous. Coupled with the reason why Viola crossdresses in the first place, it's also a Love Dodecahedron.

Literature

 * The main three characters in The Rules of Attraction, though they also each have several side-flings.

Live-Action TV

 * An episode of The Thin Blue Line uses this plot.

Theatre

 * See Twelfth Night: Orsino in the 'a' spot, Olivia at 'b', and Cesario/Viola on third.
 * A Midsummer Night's Dream becomes this once Puck goods up at applying the love potion.

3. Bob and Charlie want Alice. Alice is neutral toward, or not initially thinking in romantic terms of Bob and Charlie, or thinking about them at all.
Not a bad situation to be in, if you are Alice, though obviously a bit less so for Bob and Charlie. Some Alices will be tempted to see if there is any Type 7 (below) potential in the situation.

Anime and Manga

 * The manga Ichiroh! gives us 'a' as main character Nanako with 'b' as her childhood friend Shino and 'c' as her brother. Nanako is painfully aware of their feelings, but can't seem to discourage either of them, leaving the two to fight between each other for her.
 * Ren (A) and his two best friends (a guy and a girl) in Kaze no Stigma, who are quite jealous of each other.
 * Both versions of My-HiME contain type 3 triangles involving the main character(s):
 * (anime) Reito (B) and Yuuichi (C) are both attracted to Mai (A).
 * (manga) Yuuichi (A) is sought after by Mai (B) and Natsuki (C), since he is the "Key" to both of their HiME powers. Eventually, Shiho also tries to claim him.
 * In the Mazinger trilogy (Mazinger Z, Great Mazinger, UFO Robo Grendizer), Sayaka and Maria both want The Hero (The Lancer in the third series) and Chaste Hero Kouji Kabuto, who is usually too busy to think about romance (and is usually too dense to notice).
 * In Axis Powers Hetalia, Greece and Turkey both like Japan who backs out of telling them which one he prefers. Word of God even defines their relationships as Greece --> Japan <-- Turkey. However, considering that the ratio of Ship Tease is heavily skewed towards Greece and Japan, many fans see this as more of a Type 4 triangle with Turkey at A, Japan at B, and Greece at C.
 * In Naruto in Part I, the two tsunderes Sakura and Ino (B and C) both like Sasuke (A), who shows no romantic interest in either. Both Naruto and Lee (B and C) have feelings for Sakura, who is in love with Sasuke and thus strongly rejects their initial advances.
 * In Digimon, Davis and TK are in love with Kari, or at least Davis is. Many fans support either, and the pairings have been known as dakari (for Davis) and takari (for TK). It is unclear who her husband is at the end of Season 2, or if it even either of the two.
 * In Mai-Otome, Arika(B) and Nina(C) over Sergay (A).

Fan Works

 * This is how Axis Powers Hetalia fanfic Gankona, Unnachgiebig, Unit&agrave; began as with Germany as B and Japan as C. They both vied over Italy who was A yet didn't know if he requited either of their feelings.

Film

 * See Sabu: Osue is at 'a', in the sights of both Sabu and Eiji, two friends from childhood.
 * Paint Your Wagon starts off as this, with Ben winning Elizabeth at auction but with the Stranger longing for her as well. Rectified temporarily when Elizabeth proposes turning this into a Type 7.
 * Star Wars appears to set up this scenario with both Han and Luke being potentially interested in Leia, but later it becomes apparent that it's Han she has feelings for

Literature

 * Anne (A), in Anne of Avonlea, with Chalie Sloane (B) and Gilbert Bylthe(C) --.

Live-Action TV

 * The Best Years has both Devon and Trent in love with Samantha in the first season. This triangle is repeated in the second season with Rich and Jake.
 * From Season 3 of Angel, Fred is A, Wesley and Gunn are B and C.

Music

 * The Girl Is Mine, by Michael Jackson and Paul McCartney.

Newspaper Comics

 * Peanuts starts here. Peppermint Patty and Marcie are both shown interested in Charlie Brown. Chuck/Charles isn't quite noticing of them...

Professional Wrestling

 * Most noticeable of late is the situation in which Daniel Bryan found himself with Monday Night RAW's resident twin tag-team teases/terrors, the Bella Twins (until they found him making out with Gail Kim—they didn't take that well).

Video Games

 * This is how Touhou Fanon portrays Marisa's effect on pretty much every other character she meets, but especially so with Patchouli and Alice. Marisa steals the precious things.
 * Final Fantasy VII Tifa and Aerith both have feelings for Cloud. But he is unaware of this fact. Events in the game clear matters up by the end. One death and one Relationship Upgrade later.
 * Mega Man Legends: Volnutt is A, with Roll Caskett at B and Tron Bonne at C

Web Comics

 * Girl Genius
 * Agatha (A), Gil (B), and Tarvek (C). Bit of a cross with Type 1, as Agatha likes both of them, and oscillates between which one she wants, but has not committed either way. An added twist is that Gil and Tarvek are each aware of the other, and hate each other (for reasons unrelated to Agatha, and have yet to be made clear).
 * Agatha and Gil have started to express their feelings for each other, making this somewhat type four-ish (With Tarvek as A and Agatha at B).
 * Castle Heterodyne clearly supports type 7, and if Gil and Tarvek resolve their issues, it would go to a type 8.
 * Trudy and Ki of General Protection Fault are both attracted to Nick, who is struggling with his feelings for the two of them and his own attitudes toward relationships. After Nick and Ki get together, this turns into a Type 4.
 * In Homestuck, both WV and AR are infatuated with PM, but PM either is oblivious/doesn't have a preference.

4. Alice wants Bob, who is already in a relationship with Claire. Bob is unaware/neutral (leaving Alice as a Hopeless Suitor), or is aware of the interest and can't/won't reciprocate.
As the most complicated set of relations which is compatible with both monogamy and heterosexuality, this is very common.

Anime and Manga

 * Saki longing for Kurumi who is devoted to Nakahito in Steel Angel Kurumi.
 * Yuzuru Narazaki (A), Yukari Fujimaru (B), and Ryo Katsuragi (C) in Penguin Revolution, first professionally (Yukari is Ryo's manager, and Yuzuru stages a very determined campaign to convince her to become his manager instead) and then romantically, with the added twist that as far as Yuzuru knows, Yukari is a man.
 * Strawberry Panic centers on two of these triangles. The first consists of Tamao, Nagisa, and Shizuma as A, B, and C respectively; the second is Yaya, Hikari, and Amane.
 * In Ranma ½, (A) Ryoga Hibiki wants (B) Akane Tendo, who is, more or less, engaged to (C) Ranma Saotome. Akane doesn't seem to notice Ryoga's crush on her and remains romantically interested in her fiancée.
 * Future GPX Cyber Formula has Randoll (A), Asuka (B), and Hayato (C). Randoll wants Asuka, but she doesn't return his affections and instead shows her affections to Hayato towards the end of the TV series. In fact, Randoll promised Asuka that if he wins the Spanish race, he gets her kiss. Needless to say, it didn't work.
 * In Kimagure Orange Road, Hikaru Hiyama (A) wants her "darling," Kyosuke Kasuga (B), who thinks of her as a younger friend or a complete annoyance (depending on the situation). Kyosuke, in turn, is very interested in the cool and standoff-ish Madoka Ayukawa (C), the first girl he met when he moved to his current neighborhood. On the surface, this is appears to be a type 5 case, except that Madoka feels the same about Kyosuke, she just doesn't always show it.
 * Over the course of Rebuild of Evangelion 2.0, Shinji (B) shows genuine interest in Rei (C), much to Asuka's (A) jealousy. Then it's revealed that Rei reciprocates Shinji's feelings but doesn't realize it yet; Asuka's reaction implies that she also had interest in Shinji but realized just now she has no chance. How much Shinji loves Rei is revealed in the finale. But Kaworu (A) STILL has his unhealthy fixation on Shinji. And let's not forget how Shinji reacted when he was forced to maul Asuka against his will. Hint: it involved a Humongous Mecha, collateral damage, and lots of angry screaming.
 * Ai Yori Aoshi, with Tina, Kaoru, and Aoi at a, b, and c, respectively. Complicated by the fact that Tina and Aoi like and respect each other.
 * In the My-HiME anime, Takeda is A, with unrequited feelings toward Natsuki at B, who is (implied to eventually return Shizuru's feelings). In the ending, despite Mai and Yuuichi becoming a couple, Reito and Shiho are still persisting in their attempts to get together wtih the partner they desire.
 * In Nogizaka Haruka no Himitsu, Shiina is A to Yuuto's B and Haruka's C. At least she gets to spend one episode largely with him in episode 7 of Season 2.
 * In Freezing, Rana is A to Kazuya's B, and Satellizer's C. Not that it stops Rana from trying to get him anyway.
 * A rather twisted variation shows up in Full Metal Panic!, with Gauron at (A), Sousuke at (B), and Kaname at (C).
 * A similarly twisted version occurs in Clover, with Bols at A, Kazuhiko at B, and Ora at C.
 * In Cardcaptor Sakura, Tomoyo (A) is in love with Sakura (B). Sakura and Syaoran (C) both have crushes on each other. Because of I Want My Beloved to Be Happy, Tomoyo takes it on herself to get the two of them together.

Comic Books

 * The most likely theories concerning Ninjette (A), Thugboy (B), and Empowered (C) is that they make up type 4 or type 6. The lech decorating Emp's coffee table apparently wants it to eventually end up as type 8, but no luck so far.

Fan Works

 * In Naruto Veangance Revelaitons, Naruto (A) still loves Sakura (B) and resents Ronan (C) for stealing her away. Sakura is quick to point out how much better Ronan is than Naruto, but is willing to have sex with him on a whim.

Film

 * The movies Unlawful Entry and Indecent Proposal.
 * Brand Upon the Brain gets bonus points for diagramming this onscreen. Guy (a) and Sis (c) fall in love with Chance (b), and also with Wendy, (b in another triangle that has the same a and c.) The individual they think is Chance is actually Wendy in drag, so both triangles resolve in Sis's favor. (Guy faints when he realizes precisely what's going on.)
 * The controversial film The Night Porter by Liliana Cavani. Ex-Nazi officer Max (B) has a very visceral attraction with ex-inmate Lucia (C) (never mind her husband, who isn't in the picture). (A) comes as

Literature

 * ended up this way, as revealed in Harry Potter and the Deathly Hallows. Also, for a short time, Harry (A) pining over Ginny (B) who is "with" Dean (C).
 * This happens several times in the Tolkien legendarium: Eowyn, Aragorn, and Arwen in Lord of the Rings, Brandir, Nienor, and Túrin in The Children of Hurin, Celebrimbor, Galadriel, and Celeborn in Unfinished Talesof Numenor and Middleearth, and both Celegorm, Lúthien, and Beren and Maeglin, Idril, and Tuor in The Silmarillion.
 * Eponine, Marius, and Cosette in Les Misérables.
 * Thai's epic poem, Khun Chang Khun Phaen, has Khun Chang (A) in love with Wanthong (B), who is already a fiancée of Khun Phaen (C), and Khun Phaen is a Casanova who pratically loves every beautiful girl he comes across, including Wanthong, but due to the multiple events of kidnapping and husband switching, the relationship of the three turns into type 7. Tragically, Wanthong ends up getting beheaded for not be able to decide who she really wants to live with.
 * In Arrow's Fall of the Heralds of Valdemar series, this is what Dirk thinks is occurring in the Love Triangle between himself, Kris, and Talia. Of course, he and Talia are really lifebonded but are in denial about it, while Kris and Talia did in fact have an affair that is now over. Add in a healthy dose of Poor Communication Kills and Drowning My Sorrows, and it takes Kris' actual death, Talia's near-death, and something akin to divine intervention to sort things out.
 * In Tales of Kolmar, Idai longed for Akhor and confessed it as soon as he was of age, but he didn't want her. Later Akhor and Lanen fell for each other, and Idai had to swallow her jealousy.

Live-Action TV

 * In Glee, Dave Karofsky is interested in Kurt, who is already in a relationship with Blaine. In addition, Sebastian has feelings for Blaine, setting up another triangle with Blaine as B and Kurt as C.
 * Arrested Development: Michael is A, Marta is B, GOB is C. Later became type 7 (and briefly type 5) when Marta returned Michael's feelings, but not long afterwards she dumped both of them when they got in a fight over her.
 * Frasier, for much of its run, with Niles at A, Daphne at B, and a series of Cs.
 * Pushing Daisies, with Olive at A, Ned at B and Chuck at C.
 * iCarly season four finale sets up like this. Sam wants Freddie, who shares an existing, complicated double sided Just Friends relationship with Carly. Freddie is is aware of Sam's interest since she kissed him, but there is nothing to suggest he likes Sam back.
 * Eastenders's triangle between Syed, Christian, and Amira fits here, with Christian at A, Syed at B, and the oblivious Amira at C.
 * Torchwood: By series 2 and 3, Gwen is at A, Jack is at B, and Ianto is at C. While Jack is quite aware of Gwen's feelings for him and ambiguously returns them, he gently pushes her toward a normal relationship with her fiance Rhys. Also, while Jack and Ianto's relationship is blatantly physical, the emotional aspects are brushed over until series 3.
 * Noah's Arc: Three examples of this type of triangle: The first is Trey, Alex, and Guy, with Guy pining after Trey who is in a relationship with Alex. The second is Noah, Wade, and Ricky (it is revealed in the movie that Ricky has been in love with Noah for some time, while Noah is happily with Wade). Noah, Wade, and Baby Gat have a similar dynamic.

Music

 * Jessie's Girl by Rick Springfield.

Theatre

 * Cyrano De Bergerac is a classic (and tragic) example: Cyrano (A) is in love with Roxane (B), who in turn loves and is loved by Christian (C). The ugly Cyrano wants Roxane to be happy above all else, so he agrees to protect Christian as they go to war, while lending his poetry and wit to Christian to ensure he'll win Roxane's heart. It gets a bit more complicated by the end, but this arrangement is the basic premise.
 * Shakespeare's A Midsummer Night's Dream, Demetrius is A, Hermia is B, Lysander is C.
 * Jean-Paul Sartre's play No Exit: Garcin and Estelle want each other, but Ines, who wants Estelle, keeps preventing this.
 * Every Gilbert and Sullivan opera except Trial By Jury, Princess Ida, and The Gondoliers uses this at least once.

Video Games

 * Mega Man Battle Network does this with Guts Man.EXE (A), Roll.EXE (B), and Mega Man.EXE (C). Their netops, however, are a type 5.
 * Mega Man Star Force Luna Platz (A) can't make up her mind whether or not she is in love with Geo Stelar/Mega Man (B), who has feelings for Sonia Strumm (C).
 * Final Fantasy IV: Kain (A) is fond of Rosa (B), but she and Cecil (C) are in love with each other.
 * In Kingdom Hearts (more prominently in the first episode but possibly in the others as well) Riku (A) has feelings for Kairi (B) but she and Sora (C) are in love with each other.
 * In Professor Layton and the Unwound Future, Layton (C) is revealed to have been in a loving relationship back in college with Claire (B), who died in an accident. At the time of her death, there were not one but two (A) figures in this quadrangle. One was her boss (A1), and it's implied that she was aware of his feelings but didn't return them, a fact which he reluctantly accepted; the other (A2) was a fellow student at their university, and there's no indication that she even knew he existed. A2 took her love for Layton much harder, and it became his Start of Darkness.
 * In Warcraft, Illidan (A) is in love with Tyrande (B), but she loves Malfurion (C), and they officially marry after the Stormrage novel.
 * X-Change Alternative 2 has a fantastically bizarre version of this. Yuuki (a guy) has his body accidentally swapped with Sayuri (a girl). So all in all, Type 2 became Type 4. Oh and the storyline also involves Type 2 (two of them) AND Type 5. In one storyline you'll get to see 3 types of love triangles.

Visual Novels

 * In Don't take it personally, babe, it just ain't your story, Alpha Bitch Taylor wants her ex-boyfriend Nolan back, but he has started a relationship with Akira. In true Alpha Bitch fashion, Taylor, already a homophobe, starts harassing Akira.

Web Comics

 * Justin, Elliot, and Sarah in El Goonish Shive. Justin's gay, Elliot's not. Earlier in El Goonish Shive, Nanase was in Sarah's place, with Sarah being in Justin's, and Elliot thinking Sarah's attraction to him isn't serious, so he doesn't respond for fear of damaging their friendship until the issue is forced.
 * In Faux Pas, both Cindy and Dusk are in love (or lust) with Randy, who believes that Dusk is more predatory than loving.
 * CRFH: April is A, Mike and Marsha are B and C. Hilarity and bloodshed ensue. After Dave gets together with Blue and Margaret's Green-Eyed Epiphany sets in, another one of these develops, with Margaret at A, Dave at B, and Blue at C.
 * Misfile had this for a short while in the story with Ash (B), Emily (A), and Missi (C). Heavily disputed that is will eventually have Emily as C and Missi as A.
 * Nina and Ed are most certainly into one another in Between Failures. Reggie is hot on Nina himself, but neither Nina nor Ed can stand him, because he's a narcissistic twit who seems to think taking responsibility for your own fuckups is optional.
 * In General Protection Fault, Ki and Trudy both are in love with Nick, but Nick eventually decides on Ki. Fooker's relationship with Sharon, having just rekindled, is put on hold when he is forced to work overseas to rebuild his cover, and while Maddie O'Hara develops feelings for him during that time, his feelings remain for Sharon.

Web Original

 * Survival of the Fittest, Imraan Al-Hariq (A) has a crush on Jessie Anderson (B), who is in a relationship with Daniel Kensrue (C).
 * Red vs. Blue has Caboose, Sheila (the tank), and Lopez (the robot mechanic). Caboose (A) loves Sheila (B), but she and Lopez (C) at least like each other more. She's fairly neutral toward Caboose, though, and the two are still friends.

Western Animation

 * Ron (A) wants Kim Possible (B), who is already in a relationship with Erik (C). Ron won't make Kim aware of his feelings with Erik still around because he is a loser compared to 'perfect' Erik, and Kim is too happy with Erik to think about Ron.
 * Disney's Beauty and the Beast: Gaston is A, Belle is B, and the Beast is C.
 * On Total Drama Island, Cody (A) likes Gwen (B), who is pretty much destined from episode 1 to be with Trent (C). Cody actually didn't realize this despite obvious clues, but decided to help set them up when he finally did.
 * And again in season three, except (C) is Duncan and Cody punches him in the face instead. Technically more of a square, though, since Duncan was already dating Courtney.
 * While not played up as much, Ezekiel (A) with his crush on Bridgette (B) who's dating Geoff (C).

5. Alice loves Bob, but Bob loves Claire. Claire doesn't have feelings for either.
Alice might try persuading Bob to give up on Claire. If Alice is Axe Crazy (or otherwise extremely jealous), she might attempt to Murder the Hypotenuse. Alternatively, Alice might just want her beloved to be happy, and try to set Claire up with Bob. This is the smallest situation directly involving at least three characters where All Love Is Unrequited.

This can potentially involve more than three people, with Claire having feelings for David, David having feelings for Emily, and so forth (perhaps even looping around to Zeke loving Alice in a dodecahedral version of Type 2.)

Anime and Manga

 * Four parties involved in Kannazuki no Miko: Otoha adores Chikane, who wants to protect Himeko, who has eyes for Souma.
 * In Slam Dunk, Sakuragi is in love with Haruko, who is in love with Rukawa (who doesn't seems to be interested in anything but basketball).
 * In Naruto Hinata has feelings for Naruto, Naruto and Lee have feelings for Sakura, and Sakura and Ino have feelings for Sasuke, who cares more about revenge than romance. In Kakashi Gaiden, Obito is in love with Rin, but never told her, and Rin is in love with Kakashi, who states he doesn't deserve her for abandoning her..
 * In Yu-Gi-Oh! 5D's, there's a Gender Flipped version with Trudge, who likes Mina, who likes Jack, who likes Carly.
 * In Tenshi ni Narumon the main triangle involves Noelle who loves Yuusuke, who loves Natsumi, who obsesses over her dead brother. Also, on the villain side, Muse loves Eros, who loves Silky, who... fixates on Noelle. And a bit more complicated one, Raphael loves Mikael who is interested in Noelle, who loves Yuusuke..
 * In Sailor Moon R, Usagi and Mamoru are in love. Prince Diamond is blinded by his love for Usagi, which makes Emerald jealous as she is in love with Diamond. Furthermore, it is hinted Sapphire was in love with Emerald, given his suspicions about Wiseman causing her death. Although Prizma and Sapphire used to be an item.
 * In Magical X Miracle, in the last chapter, it is revealed that Vaith has a crush on General Lenolora, who has a Vitriolic Best Buds version of an Patient Childhood Love Interest-type relationship with Yue, but while the friendship is mutual, the love is (probably) unrequited, given Yue's Heroic BSOD at the news.
 * In the My-HiME manga, Takeda loves Natsuki, who hardly even notices him and is in love with Yuuichi instead.
 * In Hekikai no AiON, Sheila is in love with Tatsuya who was the only aside Ariel that doesn't treat her like crap but he reject her because he's already in love with Action Girl Seine who does not corresponds his feelings.

Film

 * Commonly seen in situations where A helps B to seduce C whilst either harbouring a crush all the time or developing one as the plot unfolds, ala School Days or American Pie 2.
 * Some Kind of Wonderful has this sort of triangle with Watts as A, Keith as B, and Amanda as C.

Literature
"Das ist eine alte Geschichte, Doch bleibt sie immer neu; ''Und wem sie just passieret, Dem bricht das Herz entzwei."
 * The dynamic between Turin (C), Finduilas (B), and Gwindor (A) in The Children of Hurin is best described as a type five triangle. It also has elements of type 12: Turin is loyal to Gwindor, and Finduilas and Gwindor were ex-lovers.
 * One of Heinrich Heine's most-quoted poems, No. XXXIX of the Lyrisches Intermezzo, describes a situation like this: A young man love: A young man loves a young woman, she loves a different man who loves and marries someone else entirely. The young woman then marries somebody who happens to cross her path, leaving the first young man distraught:


 * A Song of Ice and Fire: During their childhood and teenage years, Lysa loves Petyr, and Petyr loves Lysa's sister Catelyn. This starts to veer into polyhedral territory once marriages and betrothals are added, although.
 * In Tales of Kolmar, Vilkas, Will, and Aral are all friends. Aral has an obvious crush on Vilkas, who is aware of it but doesn't want her, while Will pines after Aral, who has no idea. When Aral gives Vilkas her Anguished Declaration of Love it's seen as a betrayal to everyone; when Will gives Aral his declaration it's seen as sweet and romantic.

Live-Action TV

 * Willow wants Xander who wants Buffy the Vampire Slayer, particularly in the early part of season one. Once Buffy decides she wants Angel, it becomes quadrilateral. Ah, high school.
 * The Best Years had this love triangle in season one. Dawn had feelings for Trent, but he had feelings for Samantha instead.
 * For most of My So-Called Life, the Brian (A) - Angela (B) - Jordan (C) love triangle was of this type. Many people think it still is; the rest saw it mutate to #4. In "Life of Brian", it briefly became a rectangle with Delia (uh, A'?), but Brian quickly destroyed that with the Idiot Ball.
 * Charlie, The Waitress, and Dennis in It's Always Sunny in Philadelphia. Charlie is obsessively in love with the Waitress, who despises him. In turn, the Waitress is in love with Dennis, who is openly contemptuous of her. Each member of the triangle, as well as outsiders (such as Mac), attempt to manipulate the rest of the triangle for their own benefit.

Music

 * Quite a few Miyuki Nakajima songs. Most well-known example is "Akujo," where the singer is A, the man she's singing to B, and Mariko C.
 * In the Vocaloid song Daughter of Evil, Rin Kagamine (Daughter of Evil, as well as princess of the kingdom of yellow) falls in love with the prince of the blue kingdom by the sea, Kaito. However, he falls in love with a girl from a green land, Miku. Since Rin does not know which girl Kaito fell in love with...
 * The J. Giles Band's "Love Stinks" describes this in the first verse.
 * The Taylor Swift song "Invisible" is this. The narrator likes a guy who likes another girl, and the song is basically her trying to convince him to pick herself instead of the other girl.
 * Also the basis for the song "You Belong With Me."

Newspaper Comics

 * Peanuts: Lucy (A) is (terribly) infatuated with Schroeder (B), who's only interested in playing his piano (C). Peppermint Patty (A) likes Charlie Brown (B) but he only likes the little red-haired girl (C), who has no interest in him. Sally (A) likes Linus (B) who doesn't seem that interested in anyone. Frankly, Peanuts just runs on All Love Is Unrequited.

Theatre

 * Alls Well That Ends Well: Helena loves Bertram, who's attracted to Diana.
 * Richard Strauss's opera Arabella has Zedenka (A), Matteo (B) and Zedenka's sister Arabella (C) -- complicated by (and eventually resolved thanks to) a rich suiter Mandryka who wants Arabella.

Video Games

 * In Ace Combat 5: Chopper (A), Edge (B), and Bartlett (Blaze later) (C).
 * Mega Man Battle Network has Dex at A, with Maylu at B and Lan at C, though Maylu and Lan end up getting together.

Web Comics

 * CRFH!!! has one of these after Blue makes her entrance, with Blue at A, Dave at B, and Margaret at C. This later turns into a type 4, see above.

Web Original

 * That Guy With The Glasses: The Nostalgia Chick is A, Todd in the Shadows is B, and Obscurus Lupa is C.
 * Recently made more complicated with the inclusion of Linkara. Linkara loves Chick, who loves Todd, who loves Lupa who doesn't give a shit and Nella wants Chick to love Critic who loves the Chick but she's the Master of the Mixed Message to him.

Western Animation

 * The situation in the Legend of Zelda cartoons, edging on Type 4. Link (B) likes Zelda (C), who knows full well what a loser he is, and whenever she decides he's being cute enough to get a kiss, circumstances intervene. Meanwhile, Spryte (A) is in lust with Link, often bashing Zelda right before trying to come on to Link...who prefers his girls a little taller than three inches. (Incidentally, Spryte is one of the three girls in the series who he actually does get kissed by.)
 * In Total Drama World Tour, Sierra has a Fan Girl Crush on Cody who still has feelings for Gwen.
 * On Jimmy Two-Shoes, Peep loves Heloise, who loves Jimmy, who's Oblivious to Love.
 * Hey Arnold! originally had Helga crush on Arnold, while Arnold had a Precocious Crush on an older girl named Ruth. Ruth was later written out of the show, but the same scenario developed with Lila, who wanted to be Just Friends with Arnold. And in turn, Helga had Brainy as a Stalker with a Crush.

6. Alice wants Bob and Claire, who are already in a relationship.
In this one, the "want" may not be sexual in nature, or some or all of the players could be gay/bisexual.

Anime and Manga

 * Tatewaki Kuno in Ranma ½ is the "a" in this scenario (although he doesn't know/won't admit it), with Ranma (as a girl) and Akane as "b" and "c". Arguably, "a" could be any of the others involved in this Love Dodecahedron.
 * Sailor Moon Fanon theorizes that Rei Hino (a), Mamoru Chiba (b), and Usagi Tsukino/Sailor Moon (c) are in this stage. In canon, their relationship was more of a type 4 triangle.
 * Kyon and Mikuru (B and C) are mutually attracted to each other, while Haruhi Aa) lusts after both. And Oharuhi-sama gets what she wants... Hilarity Ensues.
 * In Love Hina, it's (humorously) implied that Mutsumi is in love with Keitaro and his destined love Naru, but that she wants to see both of them be happy together.
 * Kyoya's English voice actor thinks Kyoya is in this type of scenario as the A with Tamaki and Haruhi as the B and C, and that Kyoya is okay with this, and would rather see them happy with each other than be with either himself.
 * Rosario + Vampire plays with this a bit. Yukari is into both Tsukune and Moka, who are pretty much an Official Couple. Her plan? Push them that last mile and get in on the action.
 * In Clover, Suu has a crush on both Ora and Kazuhiko, who are in a relationship with each other.

Comic Books

 * In The Walking Dead, Carol (a) grows feelings for married couple Rick (b) and Lori Grimes (c), constantly telling them both she is in love with them, and suggesting to make a polygamous relationship work and raise one another's children together. However, she is shot down by both Rick and Lori on this idea, and berated for not focusing on being a mother to her daughter Sophia.

Film

 * Played for (very uneasy or extraordinarily guilty) laughs in Rocky Horror Picture Show, in which Dr. Frank-N-Furter (a) seduces both Brad and Janet (b, c) with practically the same dialogue in back-to-back scenes. Yes, it's that kind of movie.
 * Sophie's Choice—Stingo loves Sophie and Nathan dearly, even if not sexually in the case of Nathan.
 * In Plan B, Bruno (A) tries to seduce Pablo (B) as part of a scheme to get him to break up with Laura (C). His ultimate goal is to switch places with Pablo in this triangle as he's actually straight and Laura is his ex-girlfriend he wants to get back together with by hook or crook.

Live-Action TV

 * It's very easy (and entertaining) to read the Sid/Michelle/Tony triangle in Skins this way.
 * There has been more than one gay-themed dating show where two of the contestants chose each other over the bachelor.

Music
"He used to come and court his little Mary Ann I used to think that he was my young man But Mother caught his eye and they got married on the sly Now I have to call him Father"
 * Evoked for laughs in the Fred Godfrey song "Now I Have to Call Him Father" (the protagonist is "A"):

Web Comics

 * In the webcomic Boy Meets Boy, Tybalt (a) tries to seduce Harley (b) away from Mikhael (c), who used to be his boyfriend. It's implied that Tybalt still has residual feelings for Mikhael, so his fixation on Harley probably has to do with jealousy as much as with desire.

Web Original

 * Misfiled Dreams uses Jenny in A with Ash and Emily at B and C. As Emily puts it, Jenny is attracted to Ash, Emily, and the relationship Ash and Emily have.

Multiple Media

 * 99% of Girl-On-Girl Is Hot scenarios (the girls being B and C, obviously), usually with A fervently wishing for a "classic" threesome (Type 8).

7. The classic "affair" set up. Alice is in a relationship with Bob, but she's also in a relationship with Charlie. Both Bob and Charlie don't know each other or suspect the other connection.
Much of the drama/comedy comes from all the work needed to make sure that the space between B and C stays free from any sort of information flow. A lot of geography between the two helps, or maybe a good social divide.

 7a . This setup also reflects a number of "family versus romance" situations. For example, Alice is a widow or divorcee starting a new romance against the wishes of her children. Bob (her son) and Charlie (her new man) are all too aware of each other in this case, but do not have a friendly relationship. Alternatively, Bob is an Overprotective Dad, Alice is his daughter, and Charlie is her boyfriend.

Anime and Manga

 * In Tenchi Muyo!, both Ayeka and Ryoko love Tenchi, and he loves them back. They also hate each other, and constantly scheme to be his sole possessor. Tenchi, for his part, successfully navigates his two relationships, keeping the two in a balance in which neither decides not being with him at all would be better than sharing him.
 * The risque Touhou Doujinshi "Doll Suite" takes the usual #3 love-triangle of Marisa/Alice/Patchouli and throws it into #7 territory, with Alice being (A). Marisa, in particular, seems unhappy about having to share Alice with Patchouli, but ends up agreeing to play nice.
 * In Cowboy Bebop, Julia was in a relationship with Vicious before she and Spike fell in love. When Vicious found out, it didn't end well.
 * Averted in Sailor Moon. Mina falls in love with two men named Jack and Charlie and is trying to sneak back and forth through two dates with them at once. Why is it averted? Because Jack and Charlie are really Tiger's Eye and Hawk's Eye, competing with each other over who gets to look into Mina's dream mirror.
 * Ran from Clover loves A as a brother, but A has decidedly un-brotherly feelings for Ran. Ran, meanwhile, is also in a relationship with Gingetsu. Could also be seen as a type 4.

Comic Books

 * While it was more a problem of attraction rather than infidelity, this was a problem faced by Peter Parker back when he was with Gwen Stacy and had some feelings (mostly shallow ones) for Mary Jane Watson. Gwen seemed to have won, though her death sadly came soon after.
 * Reed and Sue are married with children, but Sue and Namor have had feelings for one another for years. They've only ever acted on them in alternate universes, but they've had a lot of alternate universes together. Later writers revealed that Reed was secretly also in the same situation with his first love/college sweetheart/ex-girlfriend Alyssa Moy.
 * Marvel is just so fond of this, especially with the X-Men: X-men Scott and Jean with Wolverine; and later X-men Jean and Scott with Emma; and now apparently Scott and Emma with Namor!
 * A pretty common place for superheroes in general to be. Writers are often divided on whether or not characters should end up married or what have you, so they introduce multiple love interests to muddy the waters. See Superman (Clark and Lois or Lana), Nightwing (Dick and Starfire or Oracle), or Batman (Bruce and Catwoman or Talia. Or Zatanna, Wonder Woman, Sasha Bordeaux...)

Fan Fiction

 * This is the second stage of Axis Powers Hetalia fanfic Gankona, Unnachgiebig, Unit&agrave;. However, no affairs ever took place. Italy (A) asked both Germany (B) and Japan (C) out. They agreed because they wanted to make their precious Italy happy even if it involved sharing him.
 * The author of an Avatar: The Last Airbender fanfic resolved a conflict between Zutara and Maiko, without killing anyone. Both Mai and Katara have relationships with Zuko in the same time, tolerating each other. Later it evolves into Type 8, when the girls fall for themselves, with Zuko's help.
 * Decks Fall, Everyone Dies contains one: a=Joey, b=Duke, c=Tristan. This leads to a Murder the Hypotenuse situation.
 * Also: a=Kaiba, b=Bandit Keith, c=Yugi. But Bandit Keith is more like a customer/opponent than an actual lover, and Yugi seems to have come to terms with this fact.

Film

 * Casablanca falls into this category, with A=Ilse, B=Rick, C=Laszlo. To be fair, it happened because Ilse thought Laszlo was dead, and the ending resolves it
 * Clint Eastwood, Lee Marvin, and Jean Seberg in Paint Your Wagon. Not necessarily an affair, so much as both Clint and Sam are consensually married to the female lead.
 * In the movie Carny, a member of the road crew of a circus or amusement park (which is what the term Carny refers to) strikes up a romance with one of the customers. She decides she also likes his brother, and has sex with him, too. Apparently this doesn't bother or affect any of them, it's as if they have no jealousy at all, and have simply decided that both of them are going to share her with each other.
 * Men with Brooms starts off as this, with A=Chris, B=Julie, and C=Amy. Eventually, Julie and Amy sit down to hash out their differences, and it is clarified that there is really no love triangle to speak of, due to Julie pretty effectively hating Chris ever since he left her at the altar years previously.

Literature

 * "The Rangers Three" in The Shadow of the Avatar trilogy go somewhere here. Sharantyr just does not want to abandon either and focus her attention on only one; Belkram and Itharr know this, but stay as the Vitriolic Best Buds they were.
 * Twilight has Jacob and Edward both after Bella. Eventually this is "fixed" when Jacob Imprinted on Bella's infant daughter.
 * In The Sky Is Everywhere, Lennie is in love with Joe, but also has "physical relations" with her dead sister's boyfriend Toby.
 * Cry it out loud for The Great Gatsby, Daisy is married to Tom Buchanan, Jay Gatsby is Daisy's ex-boyfriend who's willing to do anything to get Daisy to love him again. And Daisy actually falls in love with him again, even though she still loves Tom.
 * Shows up in the hints of the last book in the Night World series. Soul mates exist, and are usually A<-->B-type relationships. Then a main character sees the silver thread associated with soulmate bonds going from her to two guys...

Live-Action TV

 * An interesting take on this appears in Randall and Hopkirk Deceased wherein B (Marty) is dead. Normally this would leave A (Jeannie) and C (Jeff) to get on with things, but B has come back as a ghost only C can see, constantly haranguing him about it, leaving poor A oblivious to this.
 * There was an episode of Bones where Brennan decided that more than one relationship was only logical, as one person couldn't fulfill all of her needs. She wound up dating a good-looking guy who pleased her sexually but bored her intellectually, and a smart but unattractive guy she loved talking with. She insisted to Booth that they were both rational and mature, and would understand... if she ever told either of them.

Video Games

 * Half-Life 2: Eli Vance, his daughter Alyx Vance and his co-worker Judith Mossman are a mild example of type 7a. Eli and Alyx love each other, Eli and Judith may be more than friends, and Alyx does not get on with Judith.

Web Original

 * A variation occurs in Survival of the Fittest. Brendan Wallace (A) is in a relationship with Erik Laurin (B). However, Erik is secretly in love with Bobby Barron (C), who is also in love with Erik, but they don't know about it, since Bobby is in the closet and pretending to be straight, and, for all Erik is concerned, is "off-limits".
 * In Strangetown, Here we Come, a Machinomic based on The Sims 2, both Ripp (B) and Johnny (C) want Ophelia, and she wants both of them. It later develops into more of a polygamous relationship.
 * In Doctor Horribles Sing Along Blog, Villain Protagonist Dr. Horrible has an unrequited crush on Wide-Eyed Idealist Penny, who falls (sort of) in love with his archrival Captain Hammer after the latter (sort of) saves her life. However, this occurs just as Penny is also starting to have feelings for Dr. Horrible's Secret Identity, Billy, leading Dr. Horrible to attempt to Murder the Hypotenuse. Tragedy ensues.
 * In the webcomic The Dreamer, there is an interesting spin on it. Beatrice is seeing two men—only one lives in the 21st century and one is in her "head". It Makes Sense in Context, believe me.

Multiple Media

 * The Arthurian Love Triangle is generally portrayed as being either of this type, or of type #5.
 * Thinking about it, Overprotective Dads are often stuck in this; Dad B, daughter A, suitor C. B-A doesn't have to be father-daughter, of course; any other intense but familial relationship in which one party wants to strike out into their own romantic interest often plays out as this (see the Skins example above). If A and B are male Heterosexual Life Partners, and it's a more comedically inclined show, expect B to say "We never talk any more!" to A in a really whiny voice at some point.
 * Most "sailor with a girl in every port" situations are this (often with D, E, F, G,...)

8. Straight-up threesome.
In polyamorous circles, this is called a triad. It may be a Ménage à trois. Not necessarily sexual in nature. See One True Threesome and Polyamory.

Anime and Manga

 * In the Distant Finale of Shoujo Sect, this has become the case with Shinobu, Momoko, and Maya, after evolving from a type 4 at the end of the main arc (with Maya being attracted to Shinobu, who'd just started a relationship with Momoko but didn't mind Maya's feelings).
 * Hikaru, Lantis, and Eagle in Magic Knight Rayearth end up as this—though Type 9 seems to apply, as well.
 * Rentarou and twins Sara and Sojyu enjoy a happy relationship together in Futakoi Alternative. Fighting is not uncommon, but there's no competition for affection or attention.
 * Soul Eater has Death the Kid and the Thompson sisters, Liz and Patti.
 * Yuki, Natsu and Kaho in SEX, though despite the existence of romantic feelings it seems to remain fairly platonic/innocent for the time being. (Ironically, considering the title of the manga, nothing sexual happens, aside from flirting.)

Fan Works

 * This is how the relationship in Axis Powers Hetalia fanfic Gankona, Unnachgiebig, Unit&agrave; ended. Over time, Germany (B) and Japan (C) ended up falling for each other too. That made Italy (A) really happy. Their relationship officially became a polyamorous one.

Film

 * The movie version of Cabaret, although it's never really harmonious.
 * In the (awesome) French film Les Chansons d'Amour, the main character and his girlfriend of several years start a three-way relationship with a co-worker of his.

Literature

 * Eric, Beth, and Kory, the main characters of the first two books of the Bedlam's Bard series by Mercedes Lackey, are in one of these. Definitely sexual in this case; Kory is bi, Beth is attracted to both guys, and Eric spends the first book struggling with the idea that he is bi (although he doesn't struggle very hard). Results in a happy, magical (literally) threesome, at least for a while.
 * Seen in Paul Kidd's Talking Animal novel The Fangs Of Kaath when one of the three main protagonists, Raschid, marries BOTH of the others, Sandhri and Yariim, who have also been feeling a growing attraction towards each other.
 * Jun'ichiro Tanizaki's novel Manji (or Quicksand), which has at least three film adaptations and furthermore inspired the film The Berlin Affair by Liliana Cavani. Depraved Bisexual misfit beauty Mitsuko (A) hooks up bored housewife Sonoko Kakiuchi (B). Sonoko's hubby (C) wants a part of the action, and the couple grow morbidly jealous of each other. Mitsuko drugs the two so that they can only have sex with her but not with each other (turning the situation into a twisted Type 7). The affair ends with a Suicide Pact wherein only Sonoko, betrayed by the other two, lives to tell the tale.
 * A Home at the End of the World (also a film): Jonathan loves Bobby and Bobby clearly reciprocates to some degree, but is also in a sexual relationship with Clare, who loves Jonathan platonically, as he does her. For a time they all live together
 * Utau, Razi and Sarri Otter in Lois McMaster Bujold's The Sharing Knife quartet. Utau and Razi appear to be a gay couple when the unworldly protagonist first encounters them; then she finds out that as well as having a sexual relationship themselves, they're married to the same woman. In their culture, birth rates are low and marriages are often dissolved if no child is conceived, to give at least one partner a chance to have children with someone else. When Utau and Sarri didn't conceive, instead of splitting up they brought a third party into the marriage (and had a little girl). It's clear in later books that polyamory of this kind is unusual and not everyone approves.
 * Shakespeare's Sonnets. The first 126 sonnets are full of Ho Yay and written to the Fair Youth. The following 28 are written to the Dark Lady. Sonnet 144 brings the triangle full circle by implying that the Fair Youth and Dark Lady are also lovers. Of course, there is jealousy and angst, at least on the narrator's side of things, and it's not clear whether he is still involved with either at that point, indicating a potential shift to Type 4.
 * The main character in The Girl Who Circumnavigated Fairyworld In A Ship Of Her Own Making meets two witches and their shared husband. The husband is a wolf most days of the month and a human for three days; one is married to the human, and the other is married to the wolf.

Live-Action TV

 * In an episode of Dark Angel there's a (throwaway) mention of a man who hired a detective agency on his wife only to learn that she has been cheating on him with his mistress. (What's left unresolved is whether he should consider it good or bad news.)
 * An example where this diagram is not a straight-up threesome. In Hollyoaks, Nancy and Ravi were dating, but both also desired Kris, who desired both. And both ended up having an affair with Kris, without the other knowing, though it continued (but not for long) after they all found out.
 * Those who don't see the Freddie/Effy/Cook love triangle in Skins as a type 11 see it as this. Effy is attracted to Cook and Freddie, who are both into her; however, Cook and Freddie are also best friends, to the point where their affection for each other is borderline-homoerotic. The story isn't just about Effy choosing between Cook and Freddie, but also how their mutual attraction to Effy and fights over her is changing Cook and Freddie's friendship.

Theatre

 * A strange example happens in Wicked. At the beginning Glinda and Fyiero are in a relationship, while Elphaba has unrequited feelings for the latter, but also share a lot of Ho Yay moments with Glinda. With a time, Fiyero falls for Elphaba, but still dates Glinda. It’s safe to say that at some point all three parties all in love with each other.

Video Games

 * Marina, Ursula, and Vlad from Kim Stanley Robinson's Red Mars Trilogy seem to fall into this category, though we never see them closely enough to be entirely certain.
 * Sora, Riku, and Kairi's relationship in Kingdom Hearts can be interpreted as a non-sexual, mix-of-love-and-friendship version of this type. The same can be said of Roxas, Axel and Xion in Kingdom Hearts : 358/2 Days.
 * It's easy to interpret the relationship between Vyse, Aika and Fina as this in Skies of Arcadia.

Webcomics

 * The three main characters of Niels.

Web Original

 * THREESOME NO JUTSU!

9. Bob and Charlie are attracted/loyal to each other but are also attracted/loyal to Alice.
If Bob and Charlie are brothers, it's a Sibling Triangle.

Anime and Manga

 * In Macross Frontier, Sheryl and Ranka are both in love with Alto and are good friends (sometimes acting quite sisterly) with one another.
 * In Touch, twins Tatsuya and Kazuya are both in love with the same girl, Minami Asakura, who loves them both.
 * Just one of many situations in Mahou Sensei Negima, Yue and Nodoka are best friends who are both attracted to Negi. Being bookworms, both the girls are incredibly Genre Savvy as to how its likely to end and the presence of a triangle is even Lampshaded by them at one point.
 * Konoka and Setsuna both initially showed interest in Negi (enough to pactio, at least), but as the series continues it's become increasingly obvious that the two will end up together. At this point, the pairing is one step short of canon.

Fan Works

 * Pick a Mary Sue fic (more specifically, any Relationship Sue fic). Mary Sue is at 'a', of course, and B and C are occupied by lesser mortals who have been enchanted away from their sexual identities, loyalties, duties, and all other responsibilities by the mesmerizing beauty of her violet eyes. Naturally, Mary Sue is too noble to allow them to depart the Righteous Path.
 * In My Immortal, Harry Vampire (b) and Draco Darko Drako (c) are both utterly in love with Ebony Dark'ness Dementia Raven Way (a), but that doesn't stop them from having an active sexual relation.

Film

 * My Father The Hero, where a girl tells the boy she likes that her father, who has taken her on a holiday, is actually her lover. Wackiness ensues.

Literature

 * In Harry Potter, Ron and Hermione are a case of Opposites Attract. But one thing they do have in common is their shared loyalty/affection toward Harry.
 * Delia(A), Eric(B) and Fitz(C) in Vanishing Acts by Jodi Picoult, only Delia and Eric are engaged, which makes it also have elements of Triang Relation #4(with Fitz as as A, Delia as B and Eric as C). Fitz eventually, though.
 * In Vampire Academy, Dimitri and Rose are in love, but worry that their relationship will get in the way of their mutual duty to protect Lissa.
 * In Shanghai Girls, sisters Pearl(C) and May(B) both want Z.G Li (A). In Pearl's eyes, she is Z.G.'s true love, but that is not the case.  In the sequel Dreams of Joy, there is a partially platonic one going on, with both Pearl and her daughter Joy   both wanting love and affection from him.

Live-Action TV

 * This variant occurs in Doctor Who. The Doctor at A, Jack at B, and Martha at C. The Doctor, wary of relationships to himself and Jack, tries to keep all three relationships platonic.
 * In the Korean Series The First Shop of Coffee Prince, you have this trope bordering on Love Dodecahedron. Cousins Choi Han Kyul and Choi Han Sung both crunch on same two women (but not at the same time). It all sorts itself in the end.
 * In Darkest Powers, in pure Sibling Triangle fashion, Derek and Simon are brothers and best friends, but both are very attracted to Chloe. Despite this, they don't fight about it and neither wants to hurt the other. It's to the point where Derek tries to push her away and over to Simon so that his brother can be happy, but then Simon turns around and does the exact same thing upon realizing that the one Chloe likes is actually Derek. Not that Chloe is aware of this at the time, however, and remains in denial about it for a while even after Simon tells her so.

Newspaper Comics

 * In Peanuts, Peppermint Patty and Marcy are both fond of Charlie Brown but are often perceived to be more than just friends.

Video Games

 * In Final Fantasy VIII, Seifer's henchmen, Fujin and Raijin, are utterly loyal to him. As he grows more distant, they start to depend more and more on each other, eventually parting ways with their leader.
 * In Tokimeki Memorial Girl's Side, activating Rival Mode with a female friend causes this. The strength of the B-C bond (and how persistent you are in making up) determines whether she steals your guy or decides I Want My Beloved to Be Happy and tells you to take care of him for her.

Western Animation

 * In Total Drama World Tour Courtney (B) and Gwen (C) are good friends but both want Duncan (A). Since Courtney and Duncan are in relationship and Gwen has been hiding her feelings from both this has elements of Triang Relation #4.

10. Alice and Bob are in a relationship, but Bob is attracted to Charlie.
How sympathetically Bob is played depends on their gender. Similar to Type 4, but with a different point of view.

Anime and Manga

 * Maison Ikkoku: Kozue (A) is dating Godai (B) who is two wishy-washy to break up with her, while he pines over Kyoko (C)
 * School Days starts out like this. Makoto and Sekai are childhood friends, and Makoto has a crush on Kotonoha. (And Sekai has a secret crush on Makoto.) Sekai helps Makoto and Kotohona get together, turning it into a Type 7 or 8 depending on how you want to interpret Sekai and Kotohona's relationship. When Sekai and Makoto take their relationship to another level, however, It Gets Worse. Much, much worse.
 * Vampire Knight Yuki (B) chooses Kaname (A), but admits to still having feelings for Zero (C). Could also be a number seven, if Zero (still) feels the same about Yuki.

Comic Books

 * Interestingly done in the original Spider-Man comics. For a while, Peter and Mary Jane were in a relationship, but Peter wanted to be with Gwen. At the same time, Gwen and Harry were in a relationship, but Gwen wanted to be with Peter. Interestingly, both Peter and Gwen are seen sympathetically, despite their gender. Then again, the male is Spider-Man.

Film

 * Shaun of the Dead: Dianne (A) and David (B) have a relationship but.

Literature

 * Ethan Frome revolves around this kind of triangle, with Zeena at A, Ethan at B, and Mattie at C. It ends tragically.

Live-Action TV

 * Simon's attraction to Jenny despite being in a relationship with Maggie in Teachers
 * Early Niles and Daphne again, this time with Maris at A, Niles at B and Daphne at C.
 * Angel: Lilah as A, Wesley as B and Fred as C.
 * In Buffy the Vampire Slayer, Spike seemed to have trouble remembering that Harmony was his girlfriend.
 * In Downton Abbey, Mary and Matthew are clearly attracted to each other despite each being engaged to other people..

Video Games

 * Fanon likes to paint the Snake/Otacon/Naomi mess in Metal Gear Solid 4 as this. Snake(A) and Otacon(B) are even raising a child together and Naomi(C) acts as a foil for their happiness Naomi is usually portayed as only using Otacon's affections to further her own goals.

== 11. The classic affair set up with a twist. Alice is in a relationship with Bob and Charlie, but Bob becomes attracted/loyal to Charlie. Bob and Charlie may or may not know about the other's involvement with Alice.== This situation is clearly the fault of Alice, who failed to control the information flow properly. Bad philanderer! No biscuit!

Anime and Manga

 * In Toradora!, this is the case with Ryuuji (A), Minori (B) and Taiga (C). This is a very strange twist of Matchmaker Crush. Taiga is trying to set up Ryuuji (who starts to take care of her) with Minori (who is Taiga's best and initially only friend). Taiga develops an emotional dependence on Ryuuji, who develops feelings as well. It turns out that Minori already had a crush on Ryuuji, but also had strong feelings for Taiga. Taiga remains good friends, but doesn't quite reciprocate Minori's feelings. Since the Official Couple is actually the title of the show/novels, bummer for Minori. Since everyone in this triangle is too nice to betray anyone, this draws out for a while.
 * Death Note gives us L (A) obsessed with his suspects, Misa (B) in love with and obsessed with Light but teases / flirts with L, and Light (C) obsessed with L and pretending to have a relationship with Misa.
 * Another one crops up later with Takada (A) seeing both Mikami (B) and Light (C) but Mikami is also VERY loyal to Light...

Comic Books

 * Karla, Daken, and Lester of Marvel Comics Dark Avengers seem to be dancing around becoming this. Adding Daken's emotion controlling pheromones into the situation just complicates things further.

Film

 * Sho, Kei, and Yi-Che in Moon Child.

Folklore

 * Some versions of the Tristan and Isolde story portray the love triangle this way: Isolde (A) is married to Mark (C) but in love with Tristan (B), who is in love with her, but is also loyal to Mark, who is his uncle.

Literature

 * The interpretation of the Arthurian triangle that Marion Zimmer Bradley gives in The Mists of Avalon.
 * Water For Elephants, kind of: Jacob feels guilty about his attraction to Marlena at first because he is loyal to August, but

Live-Action TV

 * Rose, Jack, and The Doctor. Rose would be A, Jack would be B, and The Doctor would be C. Rose and The Doctor are heavily implied to have feelings for one another in the first season of the new Doctor Who series. When Jack shows up, its obvious that there's something between him and Rose as well. However, while Jack initially simply seems to feel competitive towards The Doctor, the feelings seem to develop into... something else. However, it's clear that things won't go beyond flirting where Jack is concerned, and the Doctor tends to flirt back at him, making this an oddly chaste and playful 8.
 * Nothing "odd" about the chasteness. The Doctor had previously been presented as asexual so they didn't want to upset the old fans. Plus, it's a family show with a primary audience of kids. The fans of this OT3 normally see it as a case of a blooming relationship tragically cut short by character death.
 * Cook/Effy/Freddie in Skins (B/C/A respectively) reaches this point at the end of series 3. Effy loves Freddie, and he loves her back, but Cook also holds affections for her, and Freddie does not want to betray Cook by going out with Effy.
 * Frasier had a variation on this with Frasier playing the role of (C). Being romantically interested in a woman (A) who was in a romantic relationship with another man (B), but is herself at least very open with Frasier. Her boyfriend, on the other hand, has no idea that Frasier is a romantic rival and thinks his constant presence is a result of his undying loyalty as a friend.
 * Downton Abbey has this with Matthew (A), Mary (B) and Lavinia (C). Matthew and Lavinia are engaged, but Matthew and Mary are still in love with each other. However, Lavinia turns out to be a sweet girl and she and Mary become close, causing Mary to feel torn between her love and her friend. (It's worth noting that Mary and Lavinia's friendship is strong enough to make them one of the more popular non-canon ships.)

Video Games

 * World of Warcraft: Malfurion Stormrage (A), his brother Illidan (B), and Tyrande (C) are in this sort of triangle. Malfurion and Tyrande are a happy couple, Illidan is loyal(at the beginning) to Malfurion, but loves Tyrande.

Web Comics

 * Incredibly, this is the resolution of the love triangle in Fans (at least where the original ending left things). By the time of The Revival, they've graduated to type 8, as Rumy and Aly both decided that It's Okay If It's You.

Western Animation

 * In King of the Hill, this is the general idea of the Dale-Nancy-John Redcorn triangle. Dale and Nancy are married, Nancy has had a years-long affair with John Redcorn (and has had his son, who Dale believes is his, being oblivious to the obvious clues), but Dale has generally positive feelings about John Redcorn who he believes merely treats his wife's headaches. Comes to a head when Dale assists John with his suit to gain land as reparations from the government, and John decides to end the affair since he cannot screw over someone who has treated him as a friend.

12. Alice and Charlie are in a relationship, often married, but Alice likes Bob and Bob likes/is loyal to Charlie.
Depending on genders this can be a hilarious or very tragic set up.

Anime and Manga

 * With all the Ho Yay floating around, it's hard not to read the main Love Triangle in Berserk this way, with Casca serving as A, Griffith as B, and Guts as C. After some developments, this setup evolves into a Type 11, then reverts back to a 12 in the most tragic way possible. If you haven't figured it out yet, relationships between people in Berserk are kind of screwed.

Film

 * The relationship between the main characters in Being John Malkovich. Craig (A) and Lotte (C) are married, but Craig falls for Maxine (B) who couldn't care less about him and is enamored instead with Lotte (but only when she's in Malkovich's body at first...yeah, it's that kind of movie).
 * The backstory to Slings and Arrows, with A being Ellen, B being Oliver, and C being Geoffrey.
 * The relationships between Johnny, Lisa, and Mark in The Room.

Folklore

 * In Arthurian legend, this is how the relationship between Guinevere (A), Lancelot (B), and Arthur (C) plays out, with Lance torn between his attraction to Gwen and his loyalty to Arthur.

Visual Novel

 * Hisao, respectively, in Katawa Shoujo. What makes this situation particularly interesting is that one bad choice on Hisao's part (when the unfortunate ) can unravel all three's relationship.

13. Alice must choose between Bob and Charlie, but Bob is also attracted to Charlie.
Could arise in a gay/bisexual situation, or could be non-sexual in nature. The non-sexual setup might be something like a boy (A) wants to please his dear old Mum (B) and wants to do naked things with his girl (C). Dear old Mum likes the girl, and monopolizes her attention with shopping trips and general girl-to-girl socializing stuff that greatly reduce C's naked-fun time.

Anime and Manga

 * Fate/stay night's sequel reveals a situation only implied before with Rider and Sakura in love with Shirou and Rider feeling supreme loyalty to Sakura. Her solution is a bit unique, though.
 * Hayate the Combat Butler has this with the titular butler at point C, Hinagiku at B and Nishizawa at A. Of course, this being a Harem Series, there's a much larger Love Dodecahedron involved.

Live-Action TV

 * Eric in That '70s Show was in the second situation for an episode. He was dating Donna and loyal to his mother, Kitty. Kitty and Donna then start going out shopping and lunching, cutting down on Eric's happy naked fun time with Donna.
 * In season one of Series/Merlin, Gwen has a bit of a celebrity, would-never-admit-it crush on Arthur, but spends most of her time pining over Merlin. Too bad Merlin is too preoccupied with his Completely Platonic Destiny Says So Soul Mate Arthur.

Web Comics

 * Penny and Aggie: Put Michelle at A, Stan at B, and Rich at C.
 * Candi: Bisexual Trevor is at A, having to choose between Laura at B and Matt at C. Laura is attracted to Matt, though she won't admit it.

Western Animation

 * All Grown Up!: in "Lost at Sea", Tommy is A, Didi, his mother, is at B, and his girlfriend Rachel is at C.