Chico,

Gay male porn doesn't pretend to be anything other than what it claims to be. In contrast, "straight" porn wants to be straight and a little bit homosexual by including girl-girl scenes but not guy-guy scenes. Straight porn is the only medium to ban the male-male interaction in movies that contain both men and women.

I would compare straight porn's banning of male-male contact to what you see in many swingers clubs. Many of these clubs ban men from interacting sexually with each other, but allow male-female and female-female contact. So, even if the male member of a heterosexual couple is bisexual, he is prevented from interacting with another male. Same sleazy philosophy any way you look at it.