trans | (no subject)

Twice in two days, I've had to deal with some "That's so gay" type comments. I know why these comments are so offensive...they equate whatever they think is 'gay' is really lame or stupid or whatever negative adjective you can attach to something, and in the process, puts down gay and lesbian people, and, by extension, trans identified people, since we're one and the same to a homophobe. Usually, when I object, I am confronted with an "it's just an expression" type excuse. Not much of an excuse, and it shouldn't matter whether I'm trans, gay, lesbian or whatever if I find the comment offensive. Does anybody have a better way of putting this into words that I can retort to the clowns using this nasty expression?