This dude read my mind.

From Overheard in NY:

Guy to group of teenagers after doors close on crowded train: You know, in this city we move in on the trains.
Girl #1: We're not tourists, you know.
Guy: Then you should know better.
Girl #1: Oh, just shut up.
Guy: Didn't your father teach you to act better?
Girl #2: Her father is dead.
Guy, after slight pause: Well, maybe that's why she's such an obnoxious little twat.