It probably started hundreds of thousands of years ago when the males went out hunting and were away from females for long periods, and older males screwed around with the younger ones. The hunter/gatherer stuff is pretty much history, but this type of same-gender sexual hierarchy behavior still goes on and is an old, proud tradition in many societies and cultures. I'd rather not say who and where though, lol.

I've also read estimates that claim over 30 percent of males in our society have had at least one homosexual encounter. Kinda makes you think that there's a lot more if it going on than people realize.