What you say when a girl who is annoying or fat is trying to get close to you and is rubbing up on you trying kiss you, hug you, hold your hand, give you a blowjob, or whatever and you dont want it. It's basically implying that shes too close and to GET THE FUCK AWAY FROM ME.
Girl: hey your cute
(trys to hold you hand and shes getting really close to you. too close)
Guy: That's my pocket
Girl:What?
Guy: (walks away)