What Gustaf said, plus I think the issue here is dudes more than gay dudes.
I think the recipe for gay male promiscuity is pretty simple: Women are very unlikely to be highly promiscuous; men are much likelier. So, a very disproportionate amount of highly promiscuous sexual encounters are going to be among gay men.
That's right, Alcon, gay men are more manly than other men - they are acting more fully 'as men' - which means flocking constantly, and with anyone that moves.
But as to why they do it in public restrooms, isn't it obvious? Because they live in a prude society.
