...and until you apologize I'm not talking to you! Phew; the character is in trouble and, despite what the other character says, isn't aware of the problem. Often this is because of the characters misreading behavioral cues, but a culture clash or misunderstanding are also likely.
A Soap Opera style plot will often have the issue specifically occur because of a third party that is trying to drive a wedge in a relationship so they break up. After only hearing One Side of the Story, the angry character has decided on a course of action, and refuses to explain their motives to their victim. The poor victim is unable to defend themselves since they don't even understand where the attack is coming from.
Subtrope of Poor Communication Kills because if the characters actually talked out the problem, there wouldn't be one. Also a subtrope to Bewildering Punishment because the character getting "punished" is "in the doghouse" until they can convince the other character (who probably isn't listening) to forgive them. A common (and maddening) form of Idiot Ball.
- Ranma ½
- This is one of the problems in Akane Tendō's relationship with Ranma Saotome, of course. She is willing to see the worst of anything slightly suspicious that Ranma does, something Ranma has actually lampshaded in the anime, jump to perverse conclusions about Ranma's goals/intentions/motivations, has been shown to consciously ignore elements of Ranma's own attempts at self-defense to prove her point and selectively remember events to further back up her opinions (manga version of Hinako's introduction), and believe the lies of people like Shampoo and Ukyō... who, by the way, are her devout rivals for Ranma's hand.
- Akane isn't the only person in Ranma ½ who does this, though... unusually, however, the other people who do so tend to be Ranma's male rivals, using this trope in relation to their particular love interest being upset and them blaming that fact on Ranma (and using it as an excuse to try and beat the hell out of him). A good example would be Ryōga and Kunō attacking Ranma after he "kissed" Akane during the first Nekoken story, an event that Ranma doesn't remember due to "Kitty Ranma" being a kind of split personality. Never mind that fact that it was Kunō who awakened "Kitty Ranma" in by exposing him to his fear of cats, but is too proud and stupid to take responsibility for the incident.
- Fushigi Boshi No Futago Hime, ep 24 has bird people being teed off at the Windmill Kingdom and setting up barricades, and all one particular messenger will say is: "Why did we take such actions? King Randa (of the Windmill Kingdom) should know the reason." Naturally, King Randa is quite clueless. Al1701 says in his review: "What adult would accuse another adult of doing something, then refuse to say what they did?" Turns out King Randa is planning to build an amusement park in their area, or at least that's what the henchmen of the Moon Kingdom are saying. Al1701 says, of the bird people simply believing them over the King, "This is a horse pill of a plot contrivance this episode's asking me to swallow."
- Tokyo Tribe 2 has this with the reason why Mera wants to kill Kai. For the first several episodes, we don't know what it is, with Mera and Skunk hitting Kai with these lines early on, in flashback and in present time. As it turns out in episode 12, what Kai did was actually a lie Skunk told Mera to break up his and Kai's friendship. The lie? That Kai pushed Fujio, Mera's girlfriend, in front of an incoming train. The truth? She committed suicide for unknown reasons, and Kai thought that she was accidentally pushed out of the crowd onto the tracks.
- The third movie of Rebuild of Evangelion deconstructs this in a brutal fashion — Asuka, Misato and Ritsuko are treating Shinji like crap and won't explain why, so Shinji has no idea for most of the movie that he, by complete accident, nearly destroyed the world. When he finds out what he did, he's desperate to fix it... but the animosity between Shinji and Asuka prevents them from finding out that if Shinji tries to undo the Near Third Impact, he'll actually finish the job.
- It goes about as badly as possible in BOTH ways. By being kept out of the loop initially Shinji doesn't find out NERV is the enemy and the Rei calling him is not the one he knew and he defects as a result. He's later actually told but hearing the full truth only causes his guilt to spiral out of control until he can't be talked out of it at all and he inadvertently follows Gendo's plan again.
- In Dangan Ronpa 3, Kyosuke Munakata went through several traumatic and character breaking moments turning him into a paranoid and half-crazed Knight Templar. This cumulates in him fatally stabbing his best friend, Juzo Sakakura, and delivering this line. He does this believing that Juzo had turned to the side of despair, after being told by Kazuo Tengan that everybody was the traitor (which was technically true but for a different reason)..
- Used in a stand-up comedy bit by Adam Ferrara. "You know what you did," his girlfriend says. "No, seriously, what's-" "Well, if you don't know, then I'm not going to tell you!" The retort? "FINE! Then don't be surprised when this shit happens again!"
- Comes up in Drew Carey's rebuttal of the whole "If women ran the world, there would be no war" idea.
Drew: Yeah, I bet nobody would ever start a fight for no reason if women ran the world! "Hello, this is England. How come we're being invaded?" "Oh, I think you know why!"
- In The Muppet Show Comic Book, Miss Piggy believes Kermit is seeing someone else, based on a cryptic and entirely fraudulent prophecy.
Piggy: If you don't know why I'm mad, there's no point in me telling you, is there?
Kermit: That doesn't make any kind of sense!
- A nonromantic variant gets played with in one issue of Catwoman. The Trickster phones in a tip to the media that gives away her identity as mayoral candidate Selina Kyle, and she flies into a rage at him for outing her — and then it turns out that it was meant as a generic political smear campaign and the identification was a coincidence. And then he legitimately figures it out.
Catwoman: How did you know?!
Trickster: Er... know what?
Catwoman: Don't play games with me!
Trickster: Please, God, oh please, help me figure out what she's talking about...
Catwoman: You... you just... made it all up...?
Trickster: Can I get a category here? It would really help me defend myself if I knew what it was that you were going nuclear over...
- X-Factor (2006):' Jamie and Theresa get into an argument, which very quickly escalates into shouting and Jamie storming out. Theresa was trying to talk to him about the fact she was pregnant because of a previous night with him, while Jamie's mind was on other matters. Monet, who'd been watching the whole thing, points out afterwards that Jamie wasn't on the same page as Theresa, using Three's Company as an example.
- In MAD, one article demonstrates the various ways parents do not follow the Constitution. When it gets to the sixth amendment's requirement that the accused be informed of what they're being charged with (see Real Life), a boy who's in trouble asks why his father is mad at him, and the father says "You know what you did! I don't have to tell you!"
- Justified in A Complete Turnabout. Maya is pissed at Phoenix and doesn't tell him why, because for all she knows he should be well aware of what the problem is. It just happens that unknown to Maya the Phoenix she's talking with is a Phoenix from Alternate Universe, who has now way of knowing what his counterpart screwed up.
- Subverted in the movie 13 Going on 30. The Alpha Bitch character tells Jennifer Garner's love interest played by Mark Ruffalo a nasty lie about her to get rid of him. Later we find out that while he has indeed been avoiding her, it's been for other reasons. ("It doesn't matter what Lucy said. I stopped trusting her after she stole my poprocks in the third grade.").
- Subverted nicely in the Will Smith film Hitch, where the object of his affections took the word of a known Smug Snake, with every reason to lie, and proceeded to break up with Hitch without explanation, then trash him in her gossip column, before confronting him at a restaurant one night. Hitch, after pausing for shock, calls her out on this and corrects her loudly in front of everyone, leaving her looking quite the fool. Then the film follows up with having her apologize and him not accept it, thus making the true climax him publicly apologizing for not accepting her apology, and begging her to come back to him.
- White Christmas. A busybody hears part of a story that makes her think the male leads are planning to exploit their old friend. She tells everyone, including the female romantic interests, who almost leave the men over it.
- There's a old British joke playing on this trope that runs, more or less, as follows: A satirist sends every Member of Parliament an anonymous telegram reading "ALL IS KNOWN: FLY AT ONCE." The next day, half of Parliament fails to show up for work. According to legend, Mark Twain once did this to his friends.
- In the episode "Mr. Monk and the Captain's Marriage", a police sergeant tells Captain Stottlemeyer that he's having an affair with Stottlemeyer's wife, and the captain is suspicious enough to have his wife followed, despite her protestations of innocence. And then he's surprised when she asks for a divorce. Though it also works the other way: Stottlemeyer's wife was planning to divorce him before any of that even happened, and flat-out refused to explain why when he asked. Given that the audience saw virtually nothing over the series to back her up, it made her look like quite a bitch.
- Stottlemeyer explains it himself to Monk in a later episode, the one where Monk gets shot. He's acting like a tremendous Jerkass to Natalie because he blames her for his injury, and she accepts it because she blames herself, and so due to essentially working round the clock taking care of Monk, wheeling him around in a wheelchair, etc., she is very nearly broken down. Stottlemeyer takes Monk aside, warns him that if he keeps acting like that Natalie will leave, then proceeds to state that he knows this because Monk is acting like Stottlemeyer himself and that that was why his wife left him.
- This happens to Dexter during his second season. His girlfriend overhears Dexter's Narcotics Anonymous sponsor, who she's already suspicious of, mention on his answering phone that they spent the night together, and walks out on him. It's true... except it just means he fell asleep with his head in her lap after talking about his terrible childhood. She is his counselor, of sorts, after all. It's not actually shown if it was on purpose but considering how Lila turns out it would make complete sense that she did it on purpose knowing Rita would be there. However, Dexter has just recently revealed that he is a drug addict and he has been lying to her about things to hide his addiction. So it is not much of a stretch for her to believe that he would cheat on her as well. At least she does not find out that he is lying about being a drug addict and is actually a serial killer. When Rita finally confronts Dexter about it, he answers truthfully: he didn't have sex with Lila that night. Rita immediately picks up on the clarification and breaks up with Dexter. They work things out in the end, though.
- Phoebe claims this to Ross in an episode. Subverted in a way in that Phoebe dreamed what Ross did, and what she dreamed was... weird.
- Inverted when Ross is supposed to have read a long tract written by Rachel about the status of their relationship, and he should have known what Rachel meant by saying "Does it or doesn't it?" Ross says, "It does," and this is what Rachel wanted to hear. But "It does" meant that Ross apologizes and admits he was wrong. This is an act of appeasement that Ross was not ready to make. And it's a problem when Rachel thinks Ross has apologized and made up, but he hasn't.
- Thomas Riker uses this to his advantage in the Star Trek: Deep Space Nine episode "Defiant". Surprised by Chief O'Brien's presence aboard the titular ship, Riker cuts O'Brien's greeting off with a hard glare and "I have nothing to say to you, Chief, and I think you know why." This is because Thomas is impersonating William Riker at the time, and knows that a close friend like O'Brien would be able to tell the difference. So, by pretending to be mad at O'Brien over some past incident, Tom gets an excuse to avoid him, while at the same time confusing him enough that he won't press the issue.
- Subverted in Veronica Mars, when Alpha Bitch Madison Sinclair claims that she and Logan had had sex. True to trope, Veronica believed this unquestioningly, and confronted Logan about it. They had.
- Tim and Marsha get into one of these in the penultimate episode of Spaced. Marsha, who believes Tim and Daisy to be a couple, has seen Tim kissing his new girlfriend and confronts him about cheating on Daisy, threatening to inform her. Tim, however, does not know this, and because Marsha does not actually explicitly say anything about what she's seen, believes that Marsha is in fact referring to a birthday cake Tim has arranged for Daisy as a nice birthday surprise. Complications, naturally, ensue.
Marsha: If you don't tell her, then I will.
Tim: But you'll spoil the surprise!
Marsha: You bastard.
- Averted in Chinese Paladin 3. When the heroine, who usually has some justification for her suspicions, angrily confronts the hero with this trope, he very sensibly replies "No, what did I do?" and explains what was going on. It's almost beautiful.
- Played with in Castle. The morning after Castle broke the rules and privately met with a murder suspect that he had previously dated, Beckett confronts him about something he's done, but doesn't actually specify what she's upset about. He thinks she knows that he kissed the suspect. It turns out she's actually scolding him for messing with her chair. It later turns out she already knew about both things, and was using this trope to mess with him.
- Sketch comedy show Almost Live! addresses this in a sketch about a game show called "What The Hell Have I Done Now?" wherein a confused husband tries to figure out why his wife is mad at him.
- Season 4 of Buffy the Vampire Slayer, episode "The Yoko Factor". Spike goes around telling Willow, Giles and Xander in turn that the others, including Buffy, have been saying various derogatory things behind their backs. What he says or implies is different for each character, but all hit at their personal vulnerabilities and they all believe him without question. This starts a massive three-way fight until Buffy walks in and is immediately attacked on all sides, only she has no clue what the others are angry about.
- Joseph in season 6 of Hell's Kitchen tries to simply say "They know who they are" when asked by Ramsay for his elimination nominees. When Ramsay chews him out for not giving a straight answer, Joseph gets violent and is immediately kicked off the show.
- Lost in Austen does this twice: It turns out that Wickham's a little more honourable than Darcy says he is. It turns out that Georgiana lied to Darcy, and Wickham went along with it to avoid ruining Darcy's good name.
- On Better Off Ted, Lem and Phil decide to get back at Linda by bringing her bagels and coffee every morning for two weeks and then suddenly stopping. When they tell this plan to Ted, he says, "Hey, you stopped bringing me bagels and coffee last week!" "You Know What You Did."
- There's a refreshing and awesome subversion on Desperate Housewives, exactly the type of show which would (and does) play it straight. Lynette thinks that Tom is having an affair with the mother of Porter's friend; Tom knows that it's actually Porter who's having the affair, but doesn't know the identity of the "girl" in question. Lynette confronts Tom about it, he's relieved that she knows which just makes her even angrier, it all seems like it's going to lead straight into an example of this trope, until... Tom, still oblivious to the fact that she's mad at him, manages to get in enough words that Lynette is able to piece together the truth. Cue Porter walking in, Lynette demanding "You're having sex with your best friend's mother?!" and an epic WTF face from Tom.
- This goes as far back as William Shakespeare. In Othello, Iago's plan only succeeds because Othello decides to believe the jealous subordinate over his beloved Desdemona, and he never tells anyone what he's angry about, only that he's angry. The rest of the cast never even thinks of asking someone other than Iago about what's going on. In King Lear, Gloucester decides to believe his embittered bastard son's claim that his legitimate son is a traitor, without thinking about motives or checking with anybody else.
- In Othello, it's not that simple. Iago is known by all the characters as "honest Iago" because he has a reputation for always telling the truth, being seen as incapable of doing anything other than tell it like it is. Add in that Iago and Othello have fought in battles many times before to the extent that Othello has built up an absolute trust in Iago, who was always with him in the heat of battle. Though Othello does not ask Desdemona about this, Iago has a hand in this, saying first that Desdemona would just deny it and then that Desdemona deceived her father to marry Othello, when Othello questions why Desdemona would betray him when she has such a loyal character.
- Also done in the play Much Ado About Nothing, but with the genders switched round. Hero and Claudio are to be married the next morning - but the evil Don John convinces the court that Hero has been sleeping around. The entire court (except for the heroes) immediately believe the deceitful Prince that previously tried to overthrow the court. Of course, in fairness, they thought they'd actually seen Hero in the act...
- Sunless Sea: The official trade embargo document on the Empire of Hands is mostly dedicated to explaining what exactly isn't allowed. When it comes to the reason why the embargo is in place, "They know what they did" is the only explanation. Most of the admiralty doesn't actually know what they did, but since the inhabitants are soul-stealing monkeys that hate humanity the embargo was probably well-deserved.
- Subverted in a subplot of the webcomic Dominic Deegan. Manipulative Bastard Neilen Everstar tries to convince the protagonist and his girlfriend, respectively, that the other is discontent with the state of their otherwise happy relationship. Dominic being a seer invalidates the first half, but given Luna's propensity toward self-loathing, one would almost expect his ploy with her to be preordained to succeed. However, this isn't the case. While Dominic being a seer makes it impossible to fool him, the reason he doesn't warn Luna is because he trusts her enough to believe she would see through the trick. He was right.
- A purely accidental version occurs in Sequential Art, where Kat slumps face-first into Art's crotch while the two are sleeping on the couch, and accuses Art of being a pervert when she wakes up to find herself in said compromising position, leaving Art confused by her outburst since he was asleep when it happened. However, she learns this little detail from Pip soon after and apologizes to a still-confused Art.
- Codename: Kids Next Door "Operation Dogfight" doesn't actually use the phrase, but it's a YKWYD plot anyway, and one that works to boot: some kid who has shot down Numbuh 2 several times walks in with a chili dog into a hobby shop where 2 is shopping and gives 2 a Death Glare. At first go, one is led to conclude that he's being all "Hey, I'M the new king of the sky now, so stay out!" However, when they both shoot each other down, the kid is all "At least I stopped you from bombing the chili dog factory," and it becomes obvious that the kid was actually giving him a "You know what you're doing" glare from having heard from the shop owner that 2 was planning to do just that. With both of their planes wrecked and out of the way, the shop owner goes off to bomb the chili dog factory himself, angry at how customers always spill chili sauce on his counter.
- Said in one episode of Foster's Home for Imaginary Friends but quickly subverted as the character who said it was joking around.
- An episode of Jimmy Two-Shoes had Beezy being haunted by a ghost. When he tries to figure out why, the ghost simply replies "You know what you did."
- In an episode of Doug, the title character manages to destroy a condemned house with a single rock to impress Patti. However, this causes her to hate him for the duration of the episode because it was her old house back when her mother was still alive. The episode is exacerbated because Patti (and later Bebe, who asks her about it on Doug's request) refuse to pass that information onto Doug. His best friend Skeeter thought he knew about it, since everyone in town knows it, forgetting that he just recently moved to town. At the end, Patti apologized for being angry at him.
- Parodied in Drawn Together. A housemate will make a disparaging remark about Tori Spelling, to which another housemate will ask "why you dissing on Tori?" The response is "she knows what she did" followed by dramatic background music.
- In that cartoon where an attempt to turn The Thing of the Fantastic Four back into human turned him into a teenage boy, he attended school and there was one episode where the bullies framed him and, when he asked the teacher why she'd want to talk to him, she said something among the lines of "As if you don't know."
- An episode of Horseland had one of the girls incorrectly blamed for spreading gossip when she was overheard talking about a celebrity with the same name as one of her friends. The rest of her friends began to snub her while she herself had no idea what was going on until episode's end. Once she knows the situation, she immediately clears everything up.
- The Powerpuff Girls:
- Blossom in the episode "A Very Special Blossom." She steals a set of golf clubs to give the Professor for Father's Day. When the heat's on (read: the Professor, seen with the clubs, is arrested for theft), she ambushes Mojo Jojo, trusses him up and tries to frame him for the theft. Buttercup and Bubbles don't believe her for a second, and a beatdown among the three takes place until Blossom confesses.
- In "Curses", the girls unwittingly pick up swearing after they overheard the Professor doing it. When they curse in school, Miss Keane washes their mouths out. When they asked what they did to deserve it, she tells them "You know perfectly well what you did."
- The infamous episode of The Flintstones where Fred unknowingly switches places with an identical tycoon who acts like a jerk to Wilma, Betty and Barney, and when Fred gets home Barney beats him up and Fred has no idea what prompted it.
- My Little Pony: Friendship is Magic
- In "For Whom the Sweetie Belle Tolls", Sweetie Belle accuses Rarity of deliberately upstaging her just like she did at her fifth birthday party, but Rarity doesn't know what she's talking about. Later in her dreams, Princess Luna flashes Sweetie Belle back to the party in question and shows her the truth behind what happened that day.
- In the episode "The Hooffields and McColts", Twilight and Fluttershy are roped into trying to end a feud between two families. When trying to find out how the feud started, both family leaders respond with "They know what they did." Twilight sees this as a sign that neither of them knows what the other did.
- When Activision fired two Infinity Ward employees for insubordination, they said something to this effect.
- Pretty much everyone alive has a story of being confronted by a friend or loved one only to be given this stock line when asking what they did wrong. Similarly, children are also subjected to this trope by their parents or teachers when they do something wrong, even if they honestly don't know what they had done wrong.
- Defied by the Sixth Amendment of the United States Constitution for the reason that some nations did this (and some still do):
In all criminal prosecutions, the accused shall enjoy the right to a speedy and public trial, by an impartial jury of the State and district wherein the crime shall have been committed, which district shall have been previously ascertained by law, and to be informed of the nature and cause of the accusation;...
- When contracting in the United States, if the company lets you go or doesn't extend your contract (as opposed to firing you), it's not uncommon for them to not explain why. This is logical, since it invariably deals with company information, and you're not part of the company anymore, but this doesn't make it any less frustrating.
- According to Yoshiyuki Tomino, this is one of the reasons for removing an episode of Mobile Suit Gundam towards its director. He's never said what that reason was, though.
- If someone is disinherited in a will, it will generally be for "reasons you are aware of" or similar language. Because the person who wrote it is not around to defend their decision, a specific reason could be contested in court, whereas vague language cannot.
- This basically happened in the correspondence which led to the fatal duel between Alexander Hamilton and Aaron Burr. Someone had apparently told Burr that Hamilton offered "a still more despicable opinion" of him. Burr demanded that Hamilton either deny it or apologize, Hamilton responded that he couldn't do either if he didn't know what he was accused of saying. Burr wanted an apology anyway. (It's quite likely that he was deliberately trying to pick a fight).
- More than one Social Media site or message board Moderator will suspend accounts and punish people while refusing to state what caused the punishment. Ironically, this can make things even more toxic when the people eventually return, because they now "know" that the people who run the site can and will ban people "for no reason", so now all sins are equal. (There's a reason sites like Wikipedia engage in "warnings" first, and go out of their way to refer to specific events when banning.)