There is only one way to (pardon the pun) combat this by troops. Boast of your heterosexuality. Work it in conversation. Be loud and proud. Walk into the barrack and pronounce....I'm straight and damn proud of it. It's only fair.
I hate to say this, but I suspect that, since the "gays" have now, effectively, been given protected minority status, that could probably be considered a form of harassment for the straights to do that.
I used to feel sorry for those sad souls who identify themselves by their sexual preference...but not anymore.
I hung out on a site several years ago, with a group of (mostly) conservatives. It was changed to a real forum, and after that, we started a "tell us a little about yourself" thread. One guy starts out with, "I'm a gay man."
So one of the other, straight guys on the site asked him why he felt he had to identify himself like that. The fag got all indignant, and a bunch of enablers stood up for him, and protected him, like he was some delicate little flower. More recently I encountered this same pretentious ass on a forum. When I wouldn't buy his "GOProud is wonderful" routine, he told me to fly away on my broom!
I've since been banned from that place, but he's still there. The irony!