Alice and Bob (though gender reversals are common here) have decided that they want to pretend to be a couple to make their exes jealous, or pretend they're Happily Married to make sure Bob isn't deported or decide that sex doesn't need to have an emotional attachment and become Friends with Benefits.
It all goes along swimmingly until Bob starts feeling something for Alice. It can start by finding out she and he are very compatible, or as a jealous Green-Eyed Epiphany when she goes off with a boyfriend or has sex with someone else. Eventually, their perfect arrangement starts to fall apart as the ground rules are broken, leading to a confrontation.
Alice may or may not have feelings for Bob, but even if she does she'll defiantly say that their time together "meant nothing to me", to which Bob will plead his love with "It meant something to me, dammit!" This might be substituted with "I felt something!" and "I felt nothing!" Of course, Bob will storm off heartbroken that the woman he loves has just shot him down like a World War One observation balloon.
If Alice really doesn't have feelings for Bob, then it's heartbreak time (happily, Bob will likely come to realize he's been thoroughly neglecting Claire and hook up with her). If her intentions were malicious, she's an Intentional Heartbreaker. If she does, she's likely been denying her feelings, something another character will have to spell out to her very plainly before she realizes she loves Bob and goes after him seeking forgiveness.
- Pretty much a given in Shoujo romantic drama animes. Especially if there's a Love Triangle or something to that effect.
- Occurs often in the manga/anime Peach Girl.
- Flay and Kira in Mobile Suit Gundam SEED. Kira did like her, but when their relationship started she was definitely in Yandere mode, so she failed to realize that she did love him until it was too late. By the time she gets her emotional issues sorted out in that department, Kira isn't around and she gets taken prisoner and it just goes downhill from there for her.
- Yu-Gi-Oh! has one of these, in an indirect and implicit way in episode 90, when Mai asks Jonouchi/Joey whether she was in the dream he had of all his friends after he's knocked out by a bolt of lightning caused by Odion pretending to be Marik, summoning Ra by using a counterfeit card in episode 89, at which point Joey gets shy/flustered and lies to her.
- In Devilman, Ryo gets his memories back, remembering he is Satan betrays Akira and leaves him with an impression that their friendship was just a lie. Not only it isn't true, Ryo is in love with Akira.
- In Rurouni Kenshin, Tomoe lost her fiance at the hands of Kenshin, and Kenshin and Tomoe pose as a married couple for a time, but then they actually fall in love, and Kenshin tells her that their marriage needn't only be for show.
- In an early episode of Haruhi Suzumiya, Kyon gets Yuki a library card, since that's the only way to get her out of the library and to the meeting with Haruhi in a reasonable timeframe. Kyon thinks nothing of it but during The Disappearance of Haruhi Suzumiya, when Yuki rewrites the world so that she's a normal human, she is careful to keep that memory.
- Early on in Full Metal Panic!, Kaname and Sousuke get into a fight after Sousuke bails on a study date for a mission and flounders hopelessly at his attempts to apologize. When Sousuke cites his duty to protect her as a reason he wishes to patch things up, Kaname blows up at him for once again prioritizing his missions over everything, tells him to stop pretending he actually cares about her when it's just his job, and insists she couldn't possibly care less about him either. It's only after she runs off that she realizes that not only does guarding her mean far more to him than just a job, but also that he genuinely believes she meant everything she said.
- Evangelion 303: Subverted. Saburo broke up with Kaworu and regretted it. He wanted to get Kaworu back but Kaworu had moved on for then, and Saburo started to wonder if Kaworu had been lying to him the whole time. However Kaworu had been just so committed.
- Shinji And Warhammer 40 K: Subverted. In chapter 36 Asuka feels betrayed and wonders if Kaworu—and even Shinji—were playing with her feelings. Shinji insisted that, although he hates Nagisa, he knows that Kaworu loves her. And Nagisa knows the same thing about Shinji.
- In Xmen Origins: Wolverine, Wolverine furiously tells this to Silver Fox when she ashamedly reveals him that their relationship was all a lie, as she was actually an undercover agent for Stryker who was sent to secretly keep an eye on him after he quit Team X. Turns out she felt the same way, despite her denials to the contrary.
- Jim and Michelle in American Pie 2 exhibit a rare mutual version of this, realizing that their rather unromantic sexual experimentation and pretending to be a couple in order to make Nadia jealous has revealed a genuine connection between them. In the next film, they get married.
- Possibly the most triumphant example being Vanilla Sky, with Tom Cruise and Cameron Diaz's characters finally hashing it out in a moving car. Cameron Diaz is driving. She's very despondent. It doesn't end well.
- Tearfully "I swallowed your cum. That means something!"
- Can't Buy Me Love, and its remake, Love Don't Cost a Thing.
- Chasing Amy has Holden tell Alyssa that she meant something to him.
- Groove has this line:
Ernie: Happens to me at least once every party. Some guy comes up to me and says "Thank you for making this happen I needed this. This really meant something to me." And they nod and I nod back.
- As does Tangled, the 2001 film.
Alan: [Crying] I loved you! Tell me I meant something to you!
- After having sex, the titular characters of Zack and Miri Make a Porno feel something for each other. Zack is the first to admit it, with Miri denying she felt anything because she thought Zack had sex with another actress and didn't reciprocate her feelings and then Zack leaving, because he thought Miri had had sex with one of the porno's actors. This may be a theme in Kevin Smith's films.
- In Life as We Know It, Holly and Messer are forced to live together like husband and wife and raise their goddaughter after her parents die. Of course, they hate each other but grow to like each other. After it gets too serious, Messer leaves for a job in Phoenix. He comes back for Thanksgiving, after which Holly gets with Sam. Messer admits that he actually loved Holly.
- In Some Kind of Wonderful, Watts tries to coach best friend Keith on his date with Amanda Jones with a Practice Kiss—followed by Keith ribbing her because she was blushing.
- In Stone Of Tears, after one of Richard's teachers (the one closest to him) is revealed as a villain (after trying to drain his gift and life out of him), Richard said that he thought she cared about him and she answered that maybe she did, and that's why she tried to drain his gift instead of bleeding it out of him—which is normally accomplished by Flaying Alive the person in question.
- At the end of The Hunger Games this happens between Peeta and Katniss. She thought their romance was all for the cameras; he truly did love her and thought she had finally begun to reciprocate.
- Cordelia in Angel has this reaction to her co-worker and potential love interest Doyle's parting kiss.
Cordelia: Doyle! I thought our kiss meant something. And instead, he—he used that moment to pass [prophetic visions] on to me. Why couldn't it have been mono or herpes?
- Cordelia (or maybe not) was later on the other side of this equation with Connor.
- This is variously played straight, averted, and subverted in layers on Chuck between the title character and his CIA handler Sarah, who pretends to be Chuck's girlfriend as a cover for most of the first two seasons. This trope contributes to a central part of the drama of the show.
- Chase says this to Cameron in House and she immediately breaks up their "friends with benefits" relationship, claiming that she warned him not to fall in love with her. She did explicitly warn him and she does end up marrying him, at least for a time before she couldn't forgive him for killing a patient on purpose, even if the patient was a terrible dictator. Or rather, she could not come to terms with his having accepted what he did (ie, would NOT undo it given the chance).
- Played beautifully straight in a later episode, leading up to them possibly getting back together. But then not (at least they got closure).
- Subtle version in Firefly: Mal and Inara dress up and pretend to be a couple to go stake out the villain of the week together at a theater. No big deal is made of this. Mal agrees to help a friend of Inara fight against the villain, one thing leads to another, Inara finds out.
- Mal gets some of this in the next episode, as he's trying to convince himself their relationship doesn't mean anything.
- Denise proposed a FWB arrangement with Brad on Boston Legal, which ended when Brad realized he wasn't comfortable with it. When she found out she was pregnant with Brad's baby, she agreed to marry him.
- Happens in Ned & Stacey during the series finale on the former's part.
- On Will & Grace, it is revealed that an old girlfriend of Leo's, Diane, is the only woman Will ever had sex with. He attempts to comfort a jealous Grace by telling her it meant absolutely nothing and he only did it to verify his gayness, whereupon Diane bursts out that it meant a lot to her and was in fact the only time she'd ever had an orgasm.
- On Friends, Rachel's old college roommate denies Rachel's claims that they once drunkenly made out, until Rachel finally kisses her again in frustration, saying "maybe you'll remember this," and the girl reveals that she does remember their first make-out and has been obsessing over it ever since, but hastily denies picturing Rachel's face while having sex with her boyfriend. Whoops.
- On Mad Men Don Draper had sex with his secretary Allison during one of his drunken binges and tries to pretend that it never happened. The woman seems to go along with it for a while and then snaps, throws stuff at him and quits.
Allison: This actually happened.
- On My Name Is Earl, when Joy was still married to Earl (but having an affair with Darnell), a recurring problem in Joy and Darnell's illicit relationship is that it's all about sex. Joy is OK with that (she actually did love Earl and wasn't ready to leave him at that point), but Darnell wants to actually go out on dates and be a real couple. Joy tells him that it's out of the question because she's already married, and the two proceed to argue. She angrily dumps him for a while, but they eventually get back together and a few years (and a Chocolate Baby) later she finally leaves Earl for Darnell.
- In Orange Is the New Black, Daya became pregnant in the midst of a Secret Relationship with Officer Bennett. She knows that because the relationship is an Unequal Pairing, he could lose his job and be imprisoned himself. When her mother won't allow her to abort, the women devise a plan to conceal the baby's real paternity. Namely, sleep with the Jerkass correction officer Mendez (better known as Porn Stache), and then make a False Rape Accusation against him. Although Daya (and really everyone else) despises Pornstache, he actually falls in love with her (or rather some idealized fantasy version of her).
- Life Is Strange: Before the Storm: Chloe mentions in her journal that she hooked up with Eliot before the start of the game, but "it didn't mean anything." It's implied she lost her virginity to him. They've drifted apart since, and Chloe spends the game pining after Rachel, but Eliot is struggling to rekindle what he thought they had. It turns out he's been stalking Chloe, culminating in him cornering her and demanding she realize how terrible Rachel is. Chloe has to call the cops on him to escape.
- Given an interesting twist in Phoenix Wright: Ace Attorney - Trials and Tribulations. Obviously Phoenix meant nothing to Dahlia but all the emotional moments Phoenix had with Dahlia were really with her substituted twin sister Iris. And to Iris, Phoenix did mean something.
- In Umineko: When They Cry, Battler's promise to Shannon that he would take her away from Rokkenjima on a white horse didn't really mean anything to Battler, since he was just trying to show off to her and he later forgot about it completely. To Shannon, however, it meant a lot, and the fact that he so easily forgot about this promise factors into quite a few of her issues.
- Played with in Questionable Content. Sven and Faye are halfway into Slap-Slap-Kiss territory when they start up a Friends with Benefits setup until Sven screws it up by sleeping with another girl. After it falls apart, they both realize that it meant something to them. Faye eventually forgives Sven, but they don't continue their relationship.
- A non-romantic version can be found in Tower of God: Hoh asks Bam if he really thought that they were friends just because of a signature on a friendship list. He did.
- This xkcd
- Strong Bad of Homestar Runner does this when he accidentally deletes an email of two lovely ladies.
- In this Robot Chicken sketch, a tentacle monster falls in love (or at least becomes infatuated) with a teenage girl, and somehow has her phone number. She, however, does not wish to pursue a relationship with the tentacle monster, and mentions that her dad would not approve.
- In a platonic version, Baby Doll from Batman: The Animated Series practically name-drops the trope when talking about how her former show (and thus sitcom family) was "real to me!"