I have to say in my lifetime I've stumbled upon more straights having sex in public toilets, particularly in clubs and bars. Not to mention the man and woman who had sex behind my house last summer.
People who get a kick out of it, or simply have no where else to go, will do it - regardless of their sexuality.
That's just messed up! lol.
Either way it's disgusting for Heterosexuals or Homosexuals to have sex in any public facility. This is exactly why I hate public restrooms...
A little public sex never killed anyone, but a bathroom isn't really the optimal location.
Andrew, surely this is more common for gays though? I would guess that due to the constraints they face the need for casual and secret encounters is a lot higher - hence public toilets.