I have a friend who makes fake puking noises whenever he sees a drag queen or crossdresser on TV. It's always irritated me, and I've always wanted to say something, but there is no way of knowing how people will react.
Part of me wonders if he's doing it just to appear macho in front of others, rather than actually being disgusted by it. I usually give him the "What are you doing?" look when he does it. But never have the courage to actually confront him.
I think you could try "What's wrong with that?". But it will probably just be answered with macho crap, so I dunno *Shrug*.