Stop being a wise guy

Meaning

A request for someone to stop being sarcastic, condescending, or overly clever. It is the classic comeback to someone who thinks they are funnier or smarter than they really are.

Sassy, dismissive

Used in a sentence

• I am asking a serious question here, so please stop being a wise guy.
• Stop being a wise guy and help me carry these groceries inside.
• You think you are so funny, but you just need to stop being a wise guy.