An annoyance.

It is quite annoying when you're talking to a guy at a bar who just won't go away, and then commits the even worse offense of casually resting his hand On Your Ass. Especially when he's prattling away in his barely understandable heavily French-accented English about how London is the best city ever (hello, he is from Paris, what the hell is he talking about? That lost him so many points right there. That, and the fact that his hand is on your ass.) Especially when you're trying to check out another guy at the other end of the bar who is much cuter, and isn't a London-based French banker who twists the conversation so that he has a lameass excuse to look you up and down. And then when you go off to the bathroom and return to talk to your friends, blatantly ignoring him, it's just head-bangingly annoying when he tries to return to talk to you. Some people should just get the message.