I'm 100% gay and I don't mind it too much. Only if the guy is really handsome. And only if the porn isn't 100% focused on the girl. Plus the girl can't look like a slut (too much makeup etc). It just turns me off completely. And it has to be anal, vaginas for some reason really disgust me… I can't even look at it, let alone see someone fuck it.
That being said I prefer gay porn... But I don't mind MMF threesomes even though I'm not aroused by women. I like the idea of two guys seeing each other naked and fucking one girl. Especially if they slowly start to interact with each other.