Professor James said:
I'm a straight man and I never really been turned on by 2 girls banging each other. Can someone explain the appeal? I guess it's because a lesbian will never be attracted to me or even a fantasy is why I'm not turned on.
you are a strangely sentient male, most guys don't pay attention or flat out ignore the whole 'she's not attracted to you and never will be' they, or at least most men i've dealt with, don't get passed the thought of 'two chicks at once' and like to imagine those women would 'want' to be graced with insert-guy-here's magnificent 'equipment'... because really, that's all they're missing, insert-guy-here's magnificent member, if the lesbians got a taste of that they'd suddenly be not-gay but totally bi/okay with that other chick still so long as its with insert-guy-here...
if i'm coming off offensive, don't take it that way, take it as cynical sarcasm as i've heard this debate/reasoning far too much and am surprised on a daily basis these kinds of people still exist...
on a more 'serious' tone, i believe it just has to do with the male instinctive-fantasy of wanting/needing more females to pass on their genes, as we see with most primates the top/alpha-male typically has a harem, so these guys are overcompensating their status, see themselves as 'alphas' (when most aren't from my experience, snark) and feel they 'deserve' those hot chicks to be making out with them, and not just each other... primitive male brain is not a smart thing, it will easily dismiss 'logic' for the sake of its vanity... again, from my personal experience

we humans, for whatever reason decided to breed in pairs mostly as our evolutionary mechanism, allowing for all males to procreate, giving all of them the 'chance' to breed and spread their genes, though the idea of having at least two wyminz is still appealing in that primate-i'm-better-then-you kind of way...
so... illogical dominance thing? sure, i'll go with that...
this question always seems funny to me because honestly, as a flipside deal, i DON'T want two men... *shutters* i don't understand Yaoists and i never will... i like my men to be MEN! for one... and two, i'm totally fine with my one mate... *shrugs*