The Missus and the Ex

""Oh mate, the missus and the ex! Welcome to every man's worst nightmare.""

- Mickey Smith, Doctor Who, "School Reunion".

Alice and Bob are in a relationship. Carol, who Bob chucked acrimoniously, turns up at a social event that the first two are attending. Either there will be a fight, Bob will get chucked by Alice or the two ladies will strike up a friendship. Either way, Bob will be highly uncomfortable. As the title implies, this is usually a guy's missus and ex, but it can go the other way, too.

Comic Books

 * In one Flash storyline, Wally West's ex Frances Kane--a magnetic powerhouse with a slight sanity problem--encounters his current lover, reporter Linda Park. There's initial tension, but by the time Wally makes the scene, they're having a good laugh over his dreadful taste in food.
 * In Spider-Man there are several occasions, usually involving Mary Jane:
 * During the "Drug issues", Mary Jane very harshly dumped Harry Osborn, which hastened his descent into drug addiction. Although she later became Peter Parker's girlfriend (and later wife), she did reconcile with Harry and she and Peter became the godparents of Harry's son Normie.
 * Mary Jane always got along well with Peter's ex-girlfriends Betty Brant and Liz Allan (later Liz Osborn). Peter also eventually became friends with Betty's fiancé Ned Leeds (though not too close) and he and MJ served as Best Man and Maid of Honor at the Brant-Leeds wedding.
 * Betty Brant Leeds had an affair with Peter Parker shortly after Mary Jane rejected his first wedding proposal, but on MJ's return to New York (ASM #242), Betty set up a date between MJ and Peter in order to bring the two back together. (Another matchmaker for Peter and MJ at the time was Liz Osborn).
 * Flash Thompson, the Best Man at the Watson-Parker wedding, had in the past dated Mary Jane.
 * As Mary Jane was re-established as Peter's love interest after his painful break-up with the Black Cat, relations between MJ and Felicia Hardy were very prickly and competitive, especially during the run-up to the Watson-Parker wedding. However, the two eventually became friends during the Clone Saga after MJ asked the Black Cat for help because she had nobody else to turn to. However, things did not always run smoothly because on some occasions MJ suspected, not without justification, that Felicia still wanted Peter.
 * In Kyle Rayner's Green Lantern run, his ex-girlfriend, Donna Troy, showed up at his art gallery showing, leading to tensions between Kyle and then-girlfriend Jade. (Donna and Jade, when they both became Kyle's exes, eventually went on to be teammates in the Outsiders and the Justice League... with further ramifications whenever Kyle enters the mix.)

Film
"Helen: I don't understand you. No matter what you say. If Kane was my man, I'd never leave him like this. I'd get a gun. I'd fight.
 * Over My Dead Body is similar. The Ex (Eva Longoria Parker) being deceased.
 * The classic Western, High Noon, features an interesting dynamic between the hero Will Kane's sweet, proper Quaker bride Amy (played by Grace Kelly), and Helen Ramirez, a saloon owner with whom he has a history. When Kane goes alone to face off against the film's villains, Helen gives Amy a piece of her mind:

Amy: Why don't you?

Helen: He is not my man. He's yours."

Literature

 * Played with in Tamora Pierce's The Immortals quartet: Daine and Numair aren't in a relationship—they aren't even aware of their feelings yet—but when one of Numair's exes, Varice Kingsford shows up, it starts getting awkward, and Daine gets jealous.
 * In the High Profile, one of the Jesse Stone novels, Jesse's ex-wife Jenn winds up being guarded by Jesse's current squeeze Sunny Randall, and much to Jesse's relief they get along quite well and without the hostility this trope tends to result in.

Live Action TV
"Dan: You haven't worn out your welcome (at the cafe) yet?
 * Doctor Who sometimes has this dynamic with current and previous companions.
 * Example one: Rose and Sarah Jane in the above-quoted episode. They have a funny argument, but quickly become friends. As the quote also shows, Mickey is delighted to see it; mainly because Rose was his girlfriend before she unceremoniously ditched him for the Doctor.
 * In a later episode, Donna and Martha meet. The Doctor worries there'll be a repeat of the events of "School Reunion", but since Donna never seems to have any romantic attachment to the Doctor and Martha got over hers, the two become pretty friendly and pick at the Doctor a bit, who ends up wishing they would fight.
 * Amy Pond has a similar conversation with River Song in the fifth season, even though it is not entirely clear just what kind of relationship River and the Doctor have (or will have, or have had). And it's pretty clear that Amy isn't in it for the 'long-term' like Rose or Martha might have been.
 * Given that Amy's marriage is a long time ago tomorrow morning, it's understandable.
 * Turned out that, so in retrospect, the sub-text is rather averted.
 * This situation generally results in the companions having a go at the Doctor.
 * A more tragic example comes from Waterloo Road. An ex-girlfriend of Earl Kelly's showed up and Maxine chucked Earl when she discovered what he was doing to the previous girlfriend's baby (selling it)..
 * In the NCIS episode "Ex-File", Gibbs has to deal with the combination of his current girlfriend Lt. Col. Hollis Mann, his third ex-wife and his former lover Jenny Sheppard.
 * All redheads.
 * This is how the first season of Greys Anatomy ends, the characters in question being Meredith, Derek, and Addison.
 * In Two and A Half Men Alan's young, hot girlfriend Kandi starts complaining about him to his ex-wife Judith. They go out, get drunk, and Kandi moves in with Judith. In the next episode It Gets Worse, or at least weirder.
 * Mild subversion in Friends where Ross's girlfriend Emily becomes friends with his ex-wife's wife. He assumes that the interest is sexual because it's what happened last time, and is horrified.
 * In at least one episode of Cheaters, the girl being cheated on and the other girl became friends, much to the horror of the cheating boyfriend.
 * Played straight in One Tree Hill, as Karen (the ex of Dan, who got her pregnant and then left her) becomes friends with Deb (Dan's wife, whom he met after dumping Karen... and got her pregnant three months later).

Deb: No, in fact Karen made me her partner.

Dan: I hope you mean in the business."

"Drake: I can't have my current girlfriend and my ex-girlfriend in the same house. You want the universe to explode!?"
 * A Cheers episode has Lilith Crane tangling with Frasier's first wife, children's entertainer Nanny Gee (Emma Thompson).
 * Carla and Nick Tortelli's second wife Loretta were the "striking up a friendship" variant.
 * This happened in the episode Three Coins in the Dryer of Dream On. Martin imagined all kinds of craziness about them viciously fighting each other. It turned out that they were indeed rather awkward and uncomfortable with each other, but perfectly nice to each other. Martin's ex-wife only reacted with a friendly detached amusement that they had so obviously been having sex.
 * Episode 2.4 of Ashes to Ashes in which Jackie Queen shows up claiming to be pregnant with Gene's baby. Barely hidden hostility ensues between her and Alex ("are you sleeping with my future husband?"), with Alex looking horrified as Gene proposes, until and they're best buds.
 * Played with on The X-Files, though it encompassed a season and a half instead of just an episode. And while Mulder and Scully were not a couple at the time, when Mulder's ex-partner (who may be his ex-wife) shows up and tries to steal him away, Scully does not take kindly to that. It doesn't help that the ex-partner is evil, and in cahoots with CSM. And that Mulder ditches Scully several times for her, and ignores all evidence pointing to the fact that she's evil. Seeing Scully's claws come out, though, made it all worth it.
 * The entire premise of Reba, where Reba's husband cheats on her, gets his mistress pregnant, and marries the mistress. The highly obnoxious Dumb Blonde mistress wants to be friends with Reba, but Reba doesn't want anything to do with her. Hilarity Ensues.
 * There was an episide of Forever Knight in which Nick, the vampire cop, is about to get hot and heavy with Janette, the French vampire who is his sometimes friend/lover, sometimes enemy going back centuries, and Natalie, his human best friend/love interest/something walks in. There's no explosion, instead Natalie is nervous, Janette seems fascinated, and says to Natalie, "We must get together and... talk." We see the look on Nick's face and it's clear that this is not an idea he finds pleasing!
 * Played with in Eureka. Sheriff Carter enters the diner and sees (or rather the audience sees) Allison Blake (the missus), Tess Fontana (the ex and the missus' best friend), and Nathan Stark (the missus' ex-husband, and bane of Carter's existence) all sitting at a table waiting for him. Amazingly, he doesn't instantly run. In a subversion however,.
 * The season three finale of Fringe teases this scenario when Olivia (Peter's girlfriend) and Fauxlivia (Olivia's Alternate Universe counterpart who was pretending to be Olivia when she was with Peter) are suddenly brought together. However, that's the least volatile pair who are suddenly brought together at the same time, and then other stuff happened.
 * Leonard from The Big Bang Theory deals with this trope in the episode "The Engagement Reaction" when Priya, his current girlfriend, and Penny, his ex, become friendly. He doesn't see a problem with it until Raj brings it to his attention.
 * Happens (in a loosest sense) in the Firefly episode Trash. YoSafBridge is currently married to Monty when the pair of them encounter Monty's war buddy Malcolm Reynolds, whom she had previously married. Like most The Missus and The Ex scenarios, this doesn't work out well for her, however in this case it's because her marriage to Mal was part of a scam and all logic suggests she's pulling some sort of con on Monty as well.
 * In Scrubs, Dr. Cox comes in to find his ex-wife Jordan chatting to his new girlfriend. He greets them with "Well, isn't this horrible."
 * Gender Flipped in Merlin. Arthur and Guinevere are about to be married when Lancelot reappears. Arthur ain't happy.
 * In the Buffy episode "New Moon Rising", Willow is just starting to slide into relationship territory with Tara when her werewolf ex-boyfriend Oz comes back into town. Things simmer for a good chunk of the episode since Oz, having missed his Willow's Sudden Sexuality, doesn't realise that he's in one of these situations. When he finally gets wise, he freaks out and kinda tries to eat Tara. It's a thing.
 * At the time of Earl's Accidental Marriage to Joy, he had started dating a woman named Jessie. When Jessie (who works as a receptionist at a bail bond clerk's office) hears that Joy has a bounty on her head for failing to appear in court, she volunteers to bring Joy in, and puts herself through Training From Hell to do so. They meet up, and Earl is afraid things will be ugly... he was right.
 * Ringer has a couple of episodes featuring the Ex and the Missus' Twin Sister Pretending to be the Missus.
 * Occurs in the Drake and Josh episode, "The Storm" when Drake's girlfriend of the week and two ex-girlfriends are at the same house party together. They constantly giggle at each other while saying Drake's name, which makes Drake freak out more.


 * The Cosby Show had a Thanksgiving Special in which Denise invited Martin's ex-wife to join the family for dinner. Everyone in the house (especially Martin) was on edge anticipating a horrible blow-up. However, when the ex arrived, Denise was genuinely glad to meet her and the two quickly became friends with no drama at all. It was especially sweet to see Martin's daughter, Olivia, spending time happily with her birth-mom and step-mom together.
 * An unusually non-romantic example occurs in Monk when Monk's first assistant, Sharona, comes to visit and meets his new assistant, Natalie. Although neither woman has romantic feelings for Monk, they both care about him and very protective of him, which leads to a lot of friction.

Theater

 * Blithe Spirit is all about this, with the added twist of the ex being dead.

Web Comics

 * Martha in Kevin and Kell is initially horrified to learn that she's been asked to be a bridesmaid for Danielle, who's marrying her ex-husband George, and initially says she will never warm up to her. Danielle, however, gets on her good side by making the dress the same as one she already owns, and the two become, in Fiona's words "unlikely friends".
 * In the Mega Crossover fancomic Roommates Erik's meet here here. Went slightly melancholic but it ended with mutual respect.
 * In its Spin-Off Girls Next Door James' meet as Funny Background Event here... they won't get along well.

Western Animation
"John: Why did you do that? [... ]Sending my girlfriend and my ex on the same mission?
 * Vixen (Green Lantern's girlfriend) and Shayera (GL's ex) get put on a team in Justice League "Hunter's Moon". They end up getting along pretty well.

J'onn: Difficult as it may be for you to believe, I don't take your love life into consideration when I make command decisions."

"Kim: So, Yori, are you really okay with Ron being off the market?
 * The Real Adventures of Jonny Quest episode "The Robot Spies": Race Bannon's ex-wife Estella, and his ex-girlfriend Jade, both make an appearance. Save for a few tense moments, it's not as bad as one would expect.
 * Kim Possible refused to admit that she was jealous when she first met Yori, a girl Ron made friends with while attending the Yamanouchi Ninja School. This despite Ron being oblivious to Yori's obvious attraction to him. Later, after Ron and Kim became a couple, Ron broke the news to Yori, who seemed to take it in stride. Later, when Kim and Yori were working together to retrieve a mystic monkey artifact from a temple, they bonded.

Yori: Off the market?

Kim: You know, mine.

Yori: I believe Stoppable-san is your destiny, Kim Possible. Like change, we must always welcome destiny.

Kim: Yori, you sorta, kinda rock.

Yori: Domo."

Video Games

 * Happens in Uncharted 2: Among Thieves when Nathan and Chloe unexpectedly run into Elena in war torn Nepal, causing the latter to introduce herself to Chloe as seen above. However, Nathan and Chloe aren't in a relationship per se (they seem to be more "friends with benefits" than anything).
 * Naughty Dog really loves this trope, Before this we had Ashelin and Keria in Jak 2 and 3 Who unlike Chloe and Elena, had a really cold introduction considering the already disdane the latter had with Jak knowing that he was working with a well know criminal like Krew.