I don't think human sexuality is that easily classifiible. I thought the same thing years ago about MSM, but now I realize that men who have sex with men IS the catergory, not straight, not gay or bisexual. I think some guys who fuck guys are actually straight. One of my fuck buds is like there. I call and he comes running for some head and ass, but he is straight in every other way. Another guy I know says he's straight but only fucks and gets fucked by chicks with dicks. Who am I to argue? It seems like every academic tome on sexuality is outdated or defied before it hits the presses. And the older I get and the more information I get, the less I seem to understand it.