Sonic: I thought it was obvious. I can't help it if you're slow.
At its simplest, this trope is when a character accidentally tells another character something that they didn't know because the former was under the impression that the latter already knew.
This trope can occur in the following ways:
- Alice accuses Bob of something (eg. "You were trying to steal a cookie from the cookie jar because mom got a spa coupon and you knew she would be out!") and have it backfire on her because it turns out Bob had no idea up until that point (eg. "Wait, mom's not home? Well, perfect time for me to go raid the jar!")
- A similar version to the above is when Alice invokes this trope and accuses Bob of something...literally, as in she's being vague and making it seem like she knew the whole story already (eg. "I know what you did!"), so Bob assumes she does and asks, usually something like "How did you know I stole a cookie from the cookie jar?"
- There's something that Bob doesn't know, or is not supposed to know, however Alice either doesn't realise it or thought that Bob had managed to find out and thus talks to Bob about it, with all the irony involved (eg. "You should get a pint of milk for that box of cookies Charlie gave you for your birthday." "Wait, Charlie's giving me a box of cookies?") This may lead to an Internal Reveal.
Subtrope of Saying Too Much. Sister trope to You Know What You Did, You Didn't Ask and You Just Told Me. Often results in Nice Job Breaking It, Hero or Nice Job Fixing It, Villain. Compare and contrast I'll Never Tell You What I'm Telling You!. See also Accidental Public Confession, Everybody Knew Already and Poor Communication Kills.
- In Inazuma Eleven: Ares, before Inakuni Raimon's match against Tonegawa Tousen, Anna tried to talk to Nishikage about Nosaka's brain tumour, assuming Nosaka already told his friend about his ilness. Nishikage became angry that he wasn't told.
- Sonic X: Sonic falls into this during the Egg Moon saga when he goes about destroying Eggman's Sunshine Balls, which he's using to provide the populace with artificial sunlight after his Egg Moon supposedly malfunctioned and created a permanent eclipse, and ends up making himself a Hero with Bad Publicity in the process. It isn't until Knuckles and GUN attack him that he explains his reason for doing so: the Earth and Moon are constantly in orbit, and if it had malfunctioned and stopped it would not remain stationary to the planet's sunlight as a result; Eggman has been deliberately controlling the Egg Moon to keep blocking the sun in order to sell the Sunshine Balls as part of a get-rich-quick scheme and to make himself a Villain with Good Publicity. When Knuckles demands to know why he didn't just tell them all this before he started knocking the towers down, Sonic's response is that he thought it was obvious; in fairness, it was pretty simple physics, but it's also implied Sonic was enjoying toying with the military.
- The Devil Is a Part-Timer!: During Suzuno's introduction, Emi is left confused over her ignorance of modern technology and questions where she came from. Suzuno bluntly responds she's from Ente Isla, and is taken aback that Emi didn't already know.
Emi: Okay... just to clarify, you're saying you're from Ente Isla?Suzuno: Yes, of course I am. Did you not know?[cue both girls screaming in surprise]
- Fruits Basket: This is the head maid's justification for not bothering to tell anyone that the box she gave Akito to comfort her over her father Akira's death was empty; she believed it was obvious and anyone could have figured it out on their own. Unfortunately, Ren, Akito's mentally unstable Abusive Mom, didn't figure it out, became convinced that it contained a treasure of Akira's, and went to incredible lengths to steal it from Akito on the grounds that anything Akira owned is rightfully hers. When the truth is revealed, the other maids immediately call the head maid out over not telling everyone, let alone giving Akito the box to begin with, but even then, the head maid defends her actions.
- Dungeon Keeper Ami: Multiple times, done by and to Ami:
- In "Deadline", the Avatar reveals him being attacked through his mantle this way:
"What is it Mercury? Have you come to gloat about finding a way to attack me through the Mantle?"
"I'm sorry. Please believe me, this is the first I learned of your sickness. The mantle was stolen from me, and I was going to ask for your help to get it back! I didn't even know it could be used to harm you," she blurted out.
- From "Diplomacy and Gifts":
"Disappeared?" Ami sat up in surprise. "Could you clarify, please?"
Durval tilted his head to the side in surprise. "The period during and after the battle in which you were hidden from scrying detection," he elaborated.
Up until this point, Ami hadn't even considered the possibility that getting possessed would interfere with scrying methods. She still existed, after all. She blinked twice while her mind raced, considered the implications. "This is news to me," she admitted.
- In "Deadline", the Avatar reveals him being attacked through his mantle this way:
- While very different fics, both Avenger of Steel and Infinity Crisis have a running theme in Thor (and other Asgardians) being under the mistaken impression Earth is aware of various cosmic/fantastic stuff (a long-ago war of dragons, the Infinity Stones, the existence of Atlantis and the Savage Land) and thus never feel the need to bring up what they assume is "common knowledge."
- In What Tomorrow Brings, Mertil and Gafinilan ask Ax what happened to them in the original timeline. Ax says that Gafinilan died of Soola's disease. This shocks Mertil, because Gafinilan had explained away his symptoms as "fatigue".
- The Incredibles: After making a new suit for Bob, Edna makes suits for the whole Parr family and shows them to Helen, inadvertently revealing to her that Bob has been doing superhero work behind her back. Edna says, "I assumed you knew, dahling. Why would he keep secrets from you?"
Helen: He wouldn't. Err...didn't. Doesn't!
- The Little Mermaid (1989): King Triton figures that Ariel is in love and calls Sebastian to discuss the matter. Sebastian thinks he knows that she is in love with a human, and is pressured by the King's suspicious questions so much that he cracks and blurts it out, and Triton is suddenly furious. And Sebastian realizes too late that Triton didn't know that part.
Triton: Let's see, now... Oh, who could the lucky merman be? (notices Sebastian just outside the door) Uh, come in, Sebastian.
Sebastian: [inhales deeply] I mustn't overreact. I must remain calm. (slowly walks over to Triton's throne; squeaky voice) Yes? [clears throat] Uh, yes, Your Majesty?
Triton Sebastian, I'm concerned about Ariel. Have you noticed she's been acting peculiar lately?
Triton: You know, moaning about, daydreaming, singing to herself... You haven't noticed, hmm?
Sebastian: W-well, I-I-I—
Sebastian: Hmm? (Triton gestures for Sebastian to come closer; the crab nervously obeys)
Triton: I know you've been keeping something from me...
Sebastian: (Big Gulp) Keeping... something?
Triton: About Ariel?
Sebastian: [trembling] Ariel?
Triton: In love?
Sebastian: I TRIED TO STOP HER, SIR! SHE WOULDN'T LISTEN! I told her to stay away from humans! They are bad! They are trouble! They are...
Triton: Humans? WHAT ABOUT HUMANS?!
Sebastian: Humans? [chuckles nervously] Who said anything about humans?
- Passengers (2016): Jim, Aurora, and Arthur were chatting when Jim states that there are no secrets between him and Aurora. Arthur unfortunately mistook this to mean that Aurora knew Jim woke her from cryosleep and talks to her about it, which is how she (ironically) finds out.
- In American Gods, as well as its adaptation American Gods (2017), Shadow finds Audrey's behaviour at Laura's funeral weird. When asked about it, Audrey says, "Well, I thought that would be obvious. Wait... you didn't know? Your wife died with my husband's cock in her mouth." Doubles as Everybody Knew Already, as Shadow was in prison while the affair lasted and their common friends and acquaintances did know.
- The crew in The Bands of Mourning are after the titular Bands, legendary artifacts held by the deceased Lord Ruler, which are hidden in a temple. Allik Neverfar, who shares a religion with the people who built the temple, reveals that the Bands were created by a god from their lands who came to theirs after his death. Coupled with the fact that Allik can't use his Translator Microbes at the same time as his lifesaving heating device, they don't discuss the topic long enough for them to realize that his Sovereign isn't their Lord Ruler. Allik knows that they're separate people, but not the epithet the Sovereign held in their lands: Kelsier, the Survivor.
- In the Discworld novel Men at Arms, we first see the (then) Corporal Carrot Ironfoundersson uses version 2 to amazing effect. Despite being under direct orders to leave peacefully and without protest, should the Fools' Guildmaster (Dr. Whiteface) refuse to answer his questions, Carrot manages to convince Dr. Whiteface that, not only is it in the Guildmaster's interests to answer Carrot's questions, but that the watch already knows what the Fools' Guild is hiding.note This turns out to be one of Carrot's favorite interrogation methods. Granted, Carrot had very good deductive suspicions, but no actual knowledge of what was being hidden.
- Five Find-Outers: The fourth book The Mystery of the Spiteful Letters has the protagonists find their friend Gladys has gone, however their parents remained elusive as to the details. Fatty decides to visit Mr. Goon and via acting like he knew the whole thing already, got Goon to reveal that Gladys had received a letter about her Dark and Troubled Past.
- The Jigsaw Jones series featured a mystery where a character leaves behind vague messages that they "knew what they did" in Cut And Paste Notes. In the end it's revealed the perpetrator didn't know a thing and was conducting an experiment to find out if people would be nicer if they thought they were constantly being watched (the answer was yes).
- A minor example appears in The Malloreon: Garion has recently been made king and he's periodically given money for personal expenses which he keeps in a drawer in his bedroom. His wife finds out about this, considers it very important, and asks why she didn't tell him. His answer was that he'd thought she already knew. She begins happily counting the coins, to Garion's bemusement. (She is from the kingdom that worships the god of wealth, after all.)
- In The Thrawn Trilogy of the old Star Wars Legends continuity, this is Played for Drama. Mara Jade, a Force-using ex-Imperial with an imprinted command from the Emperor that "YOU WILL KILL LUKE SKYWALKER," has fallen in with a group of Noghri, assassin aliens who remain with the Empire due to their loyalty to Darth Vader, and who are now happy to be serving the "Son of Vader." Mara has no idea, until one of them tells her, who that Son of Vader is... and when she finds out, it puts an entirely different spin on the Emperor's last command.
- In the Warrior Cats book Forest of Secrets, Fireheart knows that his nephew Cloudkit is going to face prejudice due to having been born as a house cat, and begins to give him a lecture about this, only to realize that Cloudkit's foster mother hadn't yet told him about where he was born. Needless to say, it's a bit of a shock to the young kit.
- In the Bones episode "The Death of the Queen Bee", Hodgins is chatting to Wendell (who's seeing Angela) and happens to mention Angela's pregnancy scare ("The Proof in the Pudding")... only to look at Wendell's face and realize this is news to him. Hodgins runs off and manages to find her in time for a hurried apology/warning before Wendell catches up. Discussing the hypothetical baby and how things would have played out leads to Angela and Wendell becoming Amicable Exes.
- Buffy the Vampire Slayer: In "The Yoko Factor," Xander, assuming Buffy had already told him as such, casually tells Riley everything about her relationship with Angel, including his Curse Escape Clause and how sleeping with Buffy turned him evil; it's only after he finishes the story that Xander realizes Riley didn't know beforehand. Riley is sent into Green-Eyed Monster mode, leading to a massive Cock Fight when Angel comes to town, and Buffy is understandably pissed at Xander for telling him everything in the first place.
Xander: She... kind of left that part out, huh?
Riley: Yeah, she did. That explains a lot of things that... I wish weren't explained.
- Burn Notice: As a former government spy, Michael is skilled at tricking people into revealing their secrets this way. One of his common tactics was to make vague statements about his target's businesses or illicit activities and then let their minds do the rest of the work, assuming that Michael must know more than he actually does. He can also do this in reverse, tricking two targets into betraying each other by telling them information he "Thought they already knew" (but is actually a complete lie) which makes Target A think they've been betrayed by Target B.
- Castle: After a lottery winner is killed, Castle recognizes that the winning numbers weren't his usual numbers... but they do match up with some significant dates from his recently-deceased neighbors. The victim regularly ran errands for his neighbor, so he was the one who purchased the ticket; when the neighbor died of natural causes before the drawing, the victim claimed the winning ticket as his own. Beckett tracks down the neighbor's only living relative and accuses him of killing the victim out of the belief that the lottery winnings were rightfully his... only he didn't keep in touch with his uncle and didn't know his uncle's usual numbers, so Beckett just told him that he might have a legal claim to a multi-million dollar jackpot.
- A Different World has Dwayne and Whitley's mothers visiting for Thanksgiving. The pair are accidentally caught up in a protest and arrested, calling to try and get their kids to bail them out. When Freddie drops by the jail to help her boyfriend out, she says that of course Dwayne and Whitley are having trouble getting bail money given Whitley recently lost her job, a burglar robbed their apartment and the pair are flat broke. Freddie heads off to help her friend, completely oblivious to how the two moms didn't know anything about their kids' problems.
- In the first episode of Everything's Gonna Be Okay, Matilda accidentally tells Genevieve's friends that Genevieve just had her first period, not realizing that Genevieve has been lying to her friends about having periods for the past two years.
- The Frasier Christmas Episode from Roz's pregnancy has the title character answer Roz's cell phone while she's in the toilet. It turns out to be Roz's mother and Frasier tells her a few things including that Roz is having some issues with her pregnancy. After Frasier hangs up, Roz returns and he tells her about the phone call. She tells him she hasn't told her mother about her pregnancy yet and can't wait to tell her.
- On the Friends episode "The One Where Ross Is Fine", Chandler and Monica are visiting a couple with an adopted child. Chandler mentions the adoption to the child, Owen, who didn't know he was adopted. Later, Chandler makes a joke to Phoebe about telling Frank Jr's triplets that Phoebe carried them...and notices the triplets are sitting within earshot. He then declares there's nothing left to do but go tell his one year-old niece that she was an accident.
- When Tahani brings up she has never heard Jason talk about his father in The Good Place, Jason responds that he thought he did mention Donkey Doug a few times, which he did, but considering he calls him "Donkey Doug" it wasn't clear to everyone he was talking about his father.
- In the Law & Order: Special Victims Unit episode "Fallacy," Stabler says to the suspect's boyfriend it's okay what his sexuality is and he doesn't get what he's telling him until he gets the Unsettling Gender Reveal that his girlfriend is a transgender woman.
- Schitt's Creek: David invites Patrick's parents to a Surprise Party for Patrick's birthday, assuming they know that Patrick is gay and that they are boyfriends as well as business partners. Johnny naturally assumes this as well so when he welcomes Patrick's parents to the motel, he refers to David and Patrick's romantic relationship, leading to a Forced Out of the Closet moment for Patrick.
- Alpha Protocol: Steven Heck somewhat offhandedly mentions he knew Scarlet was the assassin at Taipei after he blows her in half with a shotgun blast during the final mission; when Mike asks for clarification, Heck just mentions he thought Mike knew it all along and was just letting it slide for a chance to bed her.
Heck: "Pretty classy", I thought.
- This is how Tidus finds out the Awful Truth that Yuna will die at the end of her pilgrimage in Final Fantasy X. He never even had the chance to find out from the others (who all knew) casually talking about it because it was such a hard topic to discuss.
- Halo: Combat Evolved: 343 Guilty Spark tells Master Chief that activating Halo will destroy the Flood that are overwhelming the structure. Cortana stops Chief just before he does this because she has found out that "stopping the Flood" more specifically means "wiping out all lifeforms in the galaxy that could be used as Flood hosts". Guilty Spark, when confronted about this, admits that he thought Master Chief and the other "Reclaimers" already knew this would happen and wouldn't have any reason to hesitate.
- Octodad: In the last level of Dadliest Catch, Stacy is the only person to recognize Octodad without his trademark blue suit, and she inadvertently reveals his secret to Scarlet and Tommy.
Scarlet: It's an octopus!Tommy: (overlapping) It's an alien!Stacy: It's dad! (Tommy and Scarlet stare at her) No one else knew?
- RWBY: In Volume 8, Tyrian is surprised to discover that Emerald and Mercury genuinely had no idea what Salem's true endgame was, remarking that it should have been obvious from the second they met her. To wit, Emerald, Mercury, and Hazel all believed Salem merely planned to conquer Remnant, only for Ozpin to clarify, and Tyrian to confirm, that she actually plans to destroy it outright.
Tyrian: If you couldn't see that from the start, you must be out of your mind.
- In El Goonish Shive, Justin asks if the reason why he is excluded from the group going to save Elliot is because he is gay not knowing Sarah and Tedd didn't know he is gay and therefore accidentally outing himself to them.
- Khaos Komix: Unknown to her, Charlie is outed as Transgender to her boyfriend Jamie when her mother talks to him about her past Trans Tribulations. Played for Drama as he acts as Secret Secret-Keeper for most of a chapter while Charlie struggles with how to come out to him.
- In Poppy O'Possum, Magi Lila Moon accidentally let slip to Friedrich that there were still gods active on Flora because she forgot his clearance level. Forcing her to erase his memory of the last minute.
- A running theme in Star Wars: The Bad Batch is Tech being under the mistaken impression his fellow clones are as up to speed as he is on everything from Omega being a young clone to the behavioral chips affecting other Clone troops. He soon realizes he has to clarify this (which occasionally does turn into explaining things the team did, in fact, already know).
- Bob's Burgers: "Turkey in a Can" involves the Belchers trying to solve a mystery of who keeps shoving the turkey into the toilet. Louise accuses Gene and Tina of doing it to frame her in revenge for her siphoning from their allowance for the past 5 years, only for Gene and Tina to state that they had no idea she was stealing.
- DuckTales (2017):
Ludwig: You fellas all knew that, right? You did? [beat] Ohhhhh, you didn't. I'm gonna give you a moment to adjust everything. [somehow pulls out a harmonica and starts playing it despite being tied up]
- Djinn, the rightful owner of a lamp Scrooge found on an adventure years ago, comes looking for it. Scrooge had considered the lamp worthless and lost track of it, but because desperately wants it back (to the point of implicitly threatening violence), Scrooge and Webby keep him busy while the triplets find the lamp. When they track it to Ma Beagle's junkyard, Scrooge plans on sneaking in to retrieve it. Djinn is out of patience and storms the junkyard, demanding Ma Beagle return what she has stolen, the Lamp of the First Genie. Ma Beagle didn't know there was a genie lamp there, didn't steal anything this time, and is the legal owner of the property, meaning anything that winds up there with the trash is hers.
- Ludwig von Drake's reaction to everyone's shock at the bombshell that Webby is Scrooge's Opposite-Sex Clone.
- The Fairly OddParents: Cosmo and Wanda have a baby in "Fairly OddBaby". Fairy babies are supremely powerful to the point where having new babies was banned (or at least it should — Jorgen forgot to officially add it to the rulebook), so the fairies are understandably concerned when the baby goes missing. They barge into both the Anti-Fairy World and Pixie World accusing them of kidnapping the baby, however it turned out neither of their suspects even knew that the fairies had a new baby.
- King of the Hill: It's an extremely obvious Open Secret that Nancy Gribble is cheating on her husband Dale with John Redcorn, which led to the birth of Joseph. As it turns out, Peggy legitimately didn't know about this until over a decade after Joseph was born, and only after Hank all but flat-out told her when he realized her obliviousness to the fact. When Peggy demands to know why Hank never said anything about it before, he admits that he thought she knew already, since everyone who knows the Gribble family is aware of it (except, ironically, for Dale and Joseph themselves).
- Rocko's Modern Life: In "Who's for Dinner?", Heffer invites Rocko to have dinner with his family, who turn out to be wolves. While at the table, he mentions that Heffer never told him he was adopted, to which Heffer reacts with shock, as he didn't know either.
- Played for Laughs in What's New, Scooby-Doo? when the gang is visiting Fort Knox. The army personnel are being harassed by a local man who believes he's the rightful owner of the property, simply because his last name is Knox and he thinks that means it belongs to his family. When Scooby and Shaggy go to investigate him as the Monster of the Week, Shaggy takes his claim seriously and asks if the gold in Fort Knox belongs to him too. He is (somehow) shocked to learn that there's gold in Fort Knox.
- In Sonic Underground, the Oracle tells the Queen the prophecy of Robotnik's rise and eventual fall thanks to her and her children. He then proceeds to use this knowledge as Unsportsmanlike Gloating against Robotnik, thus alerting him the threat's existence in the first place and motivating him to actively seeking them out.
- SpongeBob SquarePants: In the episode "Enemy In-Law", Plankton falls in love with Mr. Krabs's mother and plans to marry her. Mr. Krabs assumes it's a scam to get the Krabby Patty formula out of his mother, who also knows it. Turns out Plankton was genuinely interested in her and didn't know that Mrs. Krabs knew the secret formula... until Mr. Krabs told him. Then Plankton realized that now he could use his upcoming marriage to her to get her to give him the formula. However, she breaks off the engagement before it can happen.