Funny Comeback

*I go into McDonald's and there is this fat girl making fun of this mentally disabled kid*
Me: you know, that could happen to any of us. You don't belong making fun of someone like that, what's wrong with you?
Girl: god gave me a mouth to speak and I'm going to use it
Me: well god also gave you a mouth to eat, you abused that privilege.
Girl: -speechless-
Me: oh and you might want to wipe that ketchup off your chin
Girl: *goes to wipe chin*
Me: no, your other chin