Preemptive "Shut Up"

"Shh! Even before you start. That was a preemptive 'shh!'. Just know I have a whole bag of 'shh!' with your name on it."

—Dr. Evil, Austin Powers: International Man of Mystery

Alice tells Bob to shut up, and he hasn't even said anything. However, she just knows that Bob's about to offer an opinion—or at least that he would be justified in doing so. This is often used to Lampshade Hypocritical Humor or Blatant Lies, or to forestall the obvious answer when Alice has walked into a Double Entendre or Rhetorical Question Blunder.

Similar stock responses include "Don't say it," "Don't say a word," and "Not one word." For extra humor, the person being told to shut up is occasionally He Who Must Not Be Heard. Compare Inner Monologue Conversation.

It can be an effective source of Rapid Fire Interrupting. Contrast Shutting Up Now.

Examples of Preemptive "Shut Up" include:

Comic Books

In the Don Rosa comic "Gyro's First Invention", Scrooge lectures Gyro on not being sentimental while carefully restoring his Number One Dime to its pedestal. He catches Donald Duck smirking at this and exclaims, "Oh, shut up, nephew!" Donald smugly replies, "I didn't say a word."

Film

Austin Powers: International Man of Mystery has the bit between Dr. Evil and his son, Scott Evil, where Dr. Evil says 'Shh' to anything Scott says, including almost trope-naming with 'That was a preemptive Shh'. Redone in one of the sequels with 'Zip it'.
At one point, Jennifer Jason Leigh's character in The Hudsucker Proxy gives Tim Robbins an ass-chewing liberally sprinkled with very well-timed Preemptive Shut Ups every time he starts to open his mouth in his defense.
In Snatch, the following exchange:

Errol: Oi, fuckface, was he speaking to you?
Turkish: "Fuckface." I like that. I'll have to remember that, next time I'm climbing off your mum.
Brick Top: (to Errol) Not now.

In The Avengers, Captain America (comics) needs to get somewhere with his team. When he runs into slight resistance, his presence is enough.

Steve: Son, just don't.

Interactive Fiction

In Graeme Cree and Stuart Moore's MiSTing of Stan Heller's A Fable, moving east from the first location produces the following response:

Max is in bed with his grandfather Willie.
TOM: Shut up, Crow.
CROW: Whaaat? I didn't say anything!
JOEL: Well, just don't.

Live Action TV

In That '70s Show, when Kelso shows up for the police academy not knowing that his friends gave him a Hitler mustache, his sergeant walks right up in his face, asks Kelso to explain himself, and yells for him to shut up before Kelso can even twitch.
Claire does this a lot to Cliff in the diet episode of The Cosby Show.
Angel gives one of these to Spike in the episode "Smile Time" when Spike discovers that Angel has become a puppet.
On Friends, Chandler proposes a rather transparent con to try and fool Joey. Monica responds by saying, "don't you think Joey will figure that out?" then immediately realizes how unlikely that is and cuts off Chandler's rebuttal with "I heard it."
From Sherlock:

Sherlock (examining a crime scene): Shut up.
Lestrade: I didn't say anything!
Sherlock: You were thinking. It's annoying.

Babylon 5 has a scene where Londo challenges an agent of the Regent to arrest him. After a confident boast, he is standing in the cell with G'Kar, who he pre-emptively snaps "Shut up" at.
NCIS, "The Good Samaritan":

Gibbs: Don't say it, DiNozzo.
Tony: I wasn't gonna say anything.
Gibbs: Don't think it.
Tony: Too late.

Dorothy gets in a few of these on The Golden Girls-usually phrased something like "Not a word, Ma!"

Stand-Up Comedy

Earlier in a show, Eddie Izzard talks briefly about Prince Philip and his tendency to say un-PC things (specifically, to a group of British students in China, "Don't stay here too long or you'll end up all slitty-eyed."). Later on, he's brought up again, this time among the Greeks hiding inside the Trojan Horse:

"Uh, hello. Oh! Have they gone? Oh, damn. Uh, we were just cleaning up. Yeah! I'm Agamemnon, this is Ajax, and this is Prince Philip of England. (beat) Don't say a bloody word! Do NOT say..."

Video Games

In Psychonauts, Lili gives one to Raz after he grimaces because of her ranting about a comic book.

Web Comics

Girl Genius got predictably haughty Zulenna. "And not a word from you" (though with a good comeback).
This Sequential Art.

Western Animation

Seen in My Little Pony Friendship Is Magic. Rarity and Fluttershy are both unhappy, but pretending to be excited so as not to hurt the others feelings, and confide in Twilight. Twilight realizes that just talking would solve everything, but whenever she tries, Pinkie appears out of nowhere and looks threateningly at her.
From the Phineas and Ferb special "Summer Belongs to You":

Dr. Doofenshmirtz: I know what handcuffs are, I'm not an idiot! (glares at Perry the Platypus) And not one word out of you!

- Another one in "We Call It Maze":

Phineas: Labryinths should be cool, fun, and exciting! Ferb..."
Ferb: (holds up a hand) You don't even need to say it.

Jetsons the Movie, when George walks in the house after getting stuffed into a sprocket box.

George: Don't say a word!