Go you! :) Really, for saying anything at all. I had a friend who was once almost beaten up in New Orleans (of all the places in the world) because he "looked gay" (he was wearing suspenders and a sixpence, and is, as a matter of fact, gay), but didn't notice it until I turned around and shouted "can't hear you through that closet". Which, uh. Random comment, and slightly O.o;, but it did the trick.

Coming up with something clever on the spot is hard, and it's even harder to take a comment seriously and reply with "I'm offended by that" than a stupid funny comment. *applauds* :)