Aye, I recall reading an article about how young men were more likely to want serious involvements than the women they were seeing, but I can't recall where the article was from. Anecdotally, my female friends tell me that in their casual sexual relationships with men (not one-night stands) it has for them been inevitable that the guy starts to develop inappropriate feelings. I think the comment on gay men is telling, and might shed some light back onto the hetero stereotype. Put simply, promiscuous (and/or camp) gay men are the most highly visible ones, leading to a stereotype that all gay men are promiscuous, while in reality you're probably surrounded by plenty of gay men who you just assume are straight - because they're not like what gay people are supposed to be like. It's a self-confirming stereotype.
That's true about the gay stereotype. It seems that whenever I debate equality for gays with bigots, they bring up that gay men are far more promiscuous. I just don't see why this matters? I think it was Chris Rock that said, "a man is as faithful as his options." Heterosexual men just normally have less options. -or maybe they don't, I'm not sure but one of my gay friends confirmed that promiscuity is an issue in the gay community when trying to maintain a monogamous relationship. Was he wrong?
Well, I'm no expert (obviously) so I could be wrong. Of course, that's within the "gay community" which doesn't necessarily imply that it's true for all gay men. But yeah, I remember a conversation between my ex-girlfriend's brother and another one of his sisters where he, as a gay guy, was explaining how promiscuity within the gay community changed monogamous relationships - he said usually people reached an arrangement where the odd infidelity was considered acceptable, and people who wanted a strict monogamous relationship basically either had to compromise or find themselves single again.