I've thought about this and voted "sometimes." It all depends on who it is, where it is, and what's the intent. If I'm with close friends at someone's home and their just kidding around (sometimes the women are flirting a bit), I don't mind - it's all in good fun. If it's a stranger or someone I don't particularly care for, them I'm going to warn them off (before my wife gets to them if they're female). Obviously, if it's done with some malicious intent, like trying to humiliate me in a public place, then I'm going to respond accordingly with full offense.
Dean