shut your gob
An imperative to be quiet or cease talking immediately. Can be rude, aggressive, or jocular depending on the context. Shut your gob, Bobby—no one asked for the opinion of a dork like you! A: "So, where do you think we can sell these stolen goods?" B: "Shut your gob! Don't you have enough sense not to talk about that in public?" Dave: "Wow, that Cadillac has seen better days. How much did you pay for that little gem?" Bill: "Ah, shut your gob, Dave. I think it looks just fine."