The First Cut Is the Deepest

""I would have given you all of my heart But there's someone who's torn it apart...""

- Cat Stevens

Alice and Bob have been growing closer and closer, possibly leading up to a Relationship Upgrade...only there's a problem: Alice's ex, Charlie. No, it's not that Alice is still in love with Charlie, it's that the fallout from her relationship with Charlie has left her with serious emotional baggage that must be worked out before any new relationship can succeed. Can also happen when Charlie is dead and Alice still has grief issues to work out. Will often culminate in an Epiphany Therapy session between Alice and Bob, where Alice spills all her baggage.

If the emotional baggage is not worked out, Alice and Bob may become an Anchored Ship.

Alternate names for this trope include Once Bitten, Twice Shy and Once Burned, Twice Shy.

Anime and Manga

 * Fruits Basket: Hatori's past relationship with Kana has this effect on him, and oddly enough, somewhat on Mayuko, his new flame, as well, since she was Kana's best friend, and was clearly a Shipper on Deck, even though she was in love with Hatori the whole time.
 * Inuyasha's past relationship with Kikyo causes this between him and Kagome...at least early on. When Kikyo is resurrected it becomes a whole new can of worms.
 * At the beginning of Kodomo no Omocha, child star Sana claims to be in a romantic relationship with her older manager Rei, whom she refers to as her "gigolo". After she is made to understand what's wrong with this and it looks like he may get back with his old girlfriend Asako Kurumi, she's left confused about romance, and this is one of the factors that impedes her getting together with Hayama.
 * Kyoko's dead husband on Maison Ikkoku. Comparisons to Godai happen all the time.
 * And as many readers fail to understand,
 * The Wallflower: Sunako being cruelly rejected by her first love was what caused her to retreat to the darkness in the first place and is still one of the issues (though certainly not the only one) keeping her and Kyohei an Anchored Ship.
 * Kyoko from Skip Beat! swore off love after finding out how her childhood love Sho was just using her to further his career, and this is the main reason for her being utterly oblivious to Ren's feelings for her.
 * GE - Good Ending has the main female character Kurokawa repeatedly plagued by the shadow of her ex-boyfriend, which keeps on haunting her even after she successfully gets together with Utsumi.
 * Highschool Dx D has the protagonist Issei unable to even think that the girls in his harem love him at all despite them even outright doing things in front of him, short of sex, is because he still has the scars from his ex-girlfriend. Specifically, the get killed by his first girlfriend and said girlfriend was bored of him.

Fanfic

 * Hunting the Unicorn, being a Deconstruction Fic of the But Not Too Gay portrayal of Kurt and Blaine, uses this to heartbreaking effect; Blaine lost his virginity at 16, when he believed  Sex Equals Love. He ended up getting strung along for weeks by a guy who didn't and had no intention of taking responsibility, leaving him terrified of either getting hurt again or accidentally doing the same thing to Kurt.

Film

 * Hercules: Megara's first boyfriend really soured her on men.
 * Enchanted: Robert's divorce effectively killed his belief in romance until Giselle came along.
 * Just Like Heaven had the grief variant with David's wife's death keeping him from forming any new relationships. Elizabeth thinks it's the first variety at first, and mocks him over his inability to get over being dumped.
 * In the 2008 film Get Smart, Agent 99 had this due to her bad breakup with.
 * The Princess Bride: After Westley's death, Buttercup vows to never love again. Luckily for her,.
 * In Red Eye, Rippner tries to guess Lisa's reason for her implied solitary nature and distance from men, mockingly asking her if someone broke her heart.
 * In Ice Age, this pops up slightly in the sequel, The Meltdown, when Manny admits that he is finding it hard to love Ellie because of his loyalty to and memories of his First Love.

Music
"But I'm growing wary of this game It's not easy to forget the past when we're close The person who stole my passion in the past did also romantically promised me"
 * The Trope Namer is the song by Cat Stevens, which has been covered by P.P. Arnold, Keith Hampshire, Rod Stewart, and Sheryl Crow, describing just this kind of situation.
 * The 1990s Cantopop song Soothe My Wound is as much as on this topic as the example above when Alice and Bob are already on the bed, as exemplified by the refrain:

Literature

 * Harry Potter features this in book 5. Harry starts to date Cho Chang, and everything is going well until Cho has a breakdown over the death of her ex,.
 * In Rebecca, the female protagonist believes that her husband Maxim is still carrying a torch for the titular Rebecca, his exalted dead first wife.
 * Ekatrin from the Vorkosigan Saga had a relationship with her first husband that was borderline abusive. Miles has to convince her that things could be different with him. Unfortunately, he decides to approach that task as if it were a covert ops mission...
 * Arya in the Inheritance Cycle has significant baggage related to her friend/possible lover Faolin, who was killed by Durza and his Urgal thralls at the beginning of the first book. This seriously impairs any possible relationship with Eragon, and is part of why she rejects him.
 * In The Last Herald-Mage Herald Vanyel never gets over the suicide of his first love, Tylendel. When he finally loves again, his beloved Stefen turns out to be 'Lendel reincarnated, though neither of them realize it at first.

Live Action TV

 * Chuck had this with Chuck and his ex Jill, and Sarah's ex partner (in both the cop way and the sleeping together way) with Bryce Larkin.
 * In the That '70s Show episode "Your Time is Gonna Come", shortly after Jackie starts dating with Hyde, she sees her previous boyfriend Kelso kissing with his new girlfriend, and - in the presence of Hyde - screams: "GET OFF MY BOYFRIEND!" In the next episode, she tells Hyde that she may have "leftover feelings" for Kelso "but what am I supposed to do? He was my first boyfriend!"
 * While it's not the first cut, Ted from How I Met Your Mother has to eventually admit that being left at the altar gave him some serious emotional baggage to deal with.
 * Though he did get a first cut too — the girl he lost his virginity to in high school pretended she loved him to get him into bed, ran out on him the moment they finished the deed, promised to call and didn't, and borrowed twenty dollars that she never returned.
 * This also occurred with Barney. He gave up the idea of relationships ever being more than one-night-stands after he had his heart crushed by his long-term college girlfriend Shannon, who he thought he would marry but who ended up cheating on him and leaving him for another guy.
 * In Doctor Who's television revamp, the Doctor can never seem to get over Rose Tyler. Every other companion he has quickly become aware of her and have a moment when they have a sense of being compared to her. That is, EVERY companion, including temporary ones like Jack Harkness.
 * This was true for Ten, but not for Eleven. This may be in part due to Moffat, who took over right after the Ten/Eleven regeneration, not referencing the RTD era very much. In addition, since after each regeneration the Doctor has a different personality, Eleven may just not think of Rose in the same way as Ten did.
 * After Angel left, Buffy had a very hard time moving on. It didn't help that her first attempt was Parker.
 * In Dexter Dexter and Rita's relationship is slowed by her Broken Bird status due to her ex-husband. Unusually for this trope, Dexter chose to date her because of this as it left her, like him, uninterested in sex.

Webcomics

 * Megatokyo:Erika's past with Hitoshi made her the Broken Bird she is today, and caused serious problems when she and Largo began to strike up a relationship.
 * Lately, Kimiko seems to be insinuating that Piro's past with Miho will have to be resolved before the two of them can move forward.
 * Non-ex example in Questionable Content. Faye can't reciprocate Marten's affections (though she really wants to) because of her issues as a result of seeing her father commit suicide. They do get an Epiphany Therapy session, but then become an Anchored Ship since she still has things to work out.

Western Animation

 * Avatar: The Last Airbender: Yue's departure had this effect on Sokka, leading him to be overprotective of his new girlfriend. Culminates in "The Serpent's Pass."
 * In Kim Possible, Kim was cool with her old flame Josh dating Tara, but the second cut was the deepest: when Eric turned out to be one of Drakken's synthodrones, it nearly broke her, until Ron snapped her out of her depression.

Video Games

 * The primary reason Aribeth is Oblivious to Love in the second chapter of Neverwinter Nights is that she hasn't gotten over Fenthick yet.
 * To clarify, he
 * Two examples in Final Fantasy VII and its related media. In the original game, Aerith asks Cloud if he'd ever met her first boyfriend who was also SOLDIER First Class. Several side stories in the game provide more information on him and, until her death, each has a clear impact on Aerith. Furthermore, it turns out that  Later, in Advent Children, Tifa and Cloud become closer, but his remembrance of Aerith is his major driving force.
 * Isabela's romance backstory in Dragon Age 2 gives this as the reason she is so casual about sex and resistant to any emotional attachment.
 * In Assassin's Creed Brotherhood, it's possible to unlock Ezio's Repressed Memories of his first love Cristina Vespucci and their relationship, which ultimately does not pan out well.