It Doesn't Mean Anything

Two people who are Just Friends do something that proves otherwise. Be it an Accidental Kiss, Almost Kiss, Fake-Out Make-Out, Kissing Under the Influence, or whatever. Afterwards, they will simply insist that It Doesn't Mean Anything or didn't happen. Their body language usually betrays their true feelings towards the situation, and one of the two will usually come right out and say "It Meant Something to Me".

One common version of this is when, for one reason or another, character A asks character B to pose as his/her boy/girl-friend or significant other. Usually ending up with both characters awkwardly abling through being told what a cute couple they make.

If this trope involves them insisting that a shared kiss didn't mean anything, the agreement will often be followed by a kiss.

Anime & Manga

 * Sagara and Inaba in Full Metal Panic! pretend to be boyfriend/girlfriend to impress Inaba's friends. While they are "practicing", Kaname keeps telling herself that this trope is at work.

Literature

 * Cat from the Night Huntress series insists that her attraction to Bones is caused by alcohol, instead of being revealed by it.

Live Action TV
"Xander: All right! Let's overreact, shall we? We were kissing. It doesn't mean that much. Willow: No. It just means you'd rather be with someone you hate... then be with me."
 * In Friends after Monica and Chandler sleep together for the first time, they insist to never do it again, then ask each other when they can do it again.
 * Also notably averted with Monica and Joey—Chandler and Monica are asked to explain exactly how they got together, and Monica admits that it was actually Joey she had been looking for with the intention of sleeping with him, precisely because she wanted something "stupid and meaningless". She found Chandler first and, well...
 * In Battlestar Galactica Reimagined, Apollo and Starbuck have some major drunken making out and things start getting heated before Apollo tries to slow them down, noticing that she seems to be upset. Starbuck's immediate response is to claim she just wanted an easy lay, and that there is nothing between the two of them - an obvious lie to anyone who's watched them together up until that point.
 * In Doctor Who, Martha gets kissed by the Doctor in her introductory episode. It's a genetic transfer, but she does develop a crush on him...
 * In the second season of Dead Like Me, Daisy kisses Mason and then adds, "Don't make any more of it than it is."
 * After Aeryn and John's first kiss on Farscape they both claim it was because of oxygen deprivation and a stressful moment. They also used the stress excuse for the first time they slept together.
 * The infamous Mistletoe/Caroline induced kiss in Bones eventually leads to a conversation between Booth, Bones, and Dr. Sweets, during which Bones proclaims that the kiss "was totally sexless" and "was nothing". Sweets disagrees.
 * In Community episode Debate 109 the kiss between Jeff and Annie was strategic and joyless.
 * Scrubs had JD and Carla drunkenly kiss after JD spent the night trying to convince her to forgive Turk. They both say this immediately after and maintain it after telling Turk about the incident. In this case it really didn't mean anything, but finally made Carla realize how easy it can be to make a small mistake, giving her the impetus to forgive Turk for his.
 * "It's only the drugs, right?"
 * In Buffy the Vampire Slayer, Buffy used this defense with Spike after their first kiss, second kiss, and... the rest of their "relationship".
 * When Faith (in Buffy's body) has sex with Riley Finn, his affection freaks her out so much she pulls away from him and starts babbling, "This is meaningless."
 * In "Innocence" Willow flees the room after catching Xander kissing Cordelia.


 * In How I Met Your Mother,

Webcomics

 * In Penny and Aggie, Penny reacts this way after her frenemy, Handsome Lech Stan, gives her a good-bye kiss out of habit (he'd ended up in her bedroom by accident) and they both get unexpectedly turned on. The scene pairs this trope with That Didn't Happen.
 * In Bittersweet Candy Bowl, Lucy kisses Mike after a particularly unpleasant encounter with some youth gang members. She immediately denies that it meant anything, but it obviously did for both parties.

Web Original

 * At the end of Greek Ninja,  have a moment, specifically he hugs her, in a way that is obvious it's not just casual. Such intimate contact is not common in Japan between friends, so when she questions him on it, he simply replies: 'I meant it the western way then.'

Western Animation

 * Danny Phantom and their Fake-Out Make-Out to fool The Hunter Valerie. They obviously felt something, but denies it. This continues on throughout the rest of the series.
 * When the crew goes on a cruise in Futurama, Leela pretends to be Fry's girlfriend so Zapp Brannigan will leave her alone. After she kisses Fry and Zapp leaves, she tells Fry, "That was for Zapp." Fry asks if she has anything else for him.