Occurring throughout the series, this gag typically involves Leonard and a member of the study group. Leonard cuts in on a conversation with an insult or something irrelevant, and gets a cutting remark in return. The first appearance was in the fifth episode of season one, “Advanced Criminal Law.” Although, it wasn’t until “Romantic Expressionism” that “Shut up, Leonard” was used.
“Advanced Criminal Law”
Jeff: Because everyone on this campus is nuts
Leonard: Not me!
Jeff: Oh, come on Leonard. If you’re going to argue with me, put on a bathing suit
Leonard: Hey, guys! Thanks for eating all the macaroni!
Jeff: Shut up, Leonard! Nobody even knows what you’re talking about!
Jeff: …I did eat all the macaroni. It’s messed up that he knows.
Leonard: You’re going to look like an ass in those.
Jeff: Shut up Leonard, I talked to your son on Family Day. I know all about your gambling.
Leonard: All hail Sir Eats Alone.
Jeff: Shut up Leonard, I heard about your prescription socks.
“Documentary Filmmaking: Redux”
Jeff: I’m always willing to go the extra mile to avoid doing something.
Leonard: Like sex with women.
Jeff: Shut up Leonard, you smell like mentholyptus.
“Foosball and Nocturnal Vigilantism”
Leonard: The stakes have never been higher.
Shirley: Shut up Leonard, I found your YouTube page. What’s the point in reviewing frozen pizza?
Leonard: You’re talking about it.
Shirley: Well, that is true.
“Urban Matrimony and the Sandwich Arts”
Jeff: Hello everyone, Shirley asked me to say nice things at her wedding.
Leonard: This is the rehearsal.
Jeff: Shut up Leonard! Those teenage girls you play ping-pong with are doing it ironically!
‘Introduction to Finality”
Britta: Give me some credit, Winger. What’s the worst that could happen?
Leonard: Classic tee-up.
Britta: Shut up Leonard, I know about your crooked wang.
Leonard: No such thing as bad press.
“Basic Human Anatomy”
Dean Pelton (With Jeffrey Inside Him): There you go, my work here is done. You’re one and two again. Now, you can direct your anger and resentment at each other. Congrats.
Leonard: Classic wrap-up.
Dean Pelton (With Jeffrey Inside Him): Shut up Leonard! I’ve got a picture of your old nose, it was a lateral move!
Annie (Turned on): Dean.
Annie: Why is this happening?
Leonard: I told you you’d be back.
Jeff: Shut up Leonard, I’m not here I’m just a figment of your creeping dementia.
Leonard: *blows raspberry*