However, I do have an intellectual curiosity about women's sexuality. I'm pro-sexuality for women, not grossed out by it as so many silly gays can be. I can even enjoy seeing a woman enjoying herself (and not putting on a campy, silly, big-haired, long-nailed, high-heeled, cliche porn routine for a straight guy as fake as her boobs... I mean actually enjoying her own sexuality.) But I've just never been sure what it has to do with me. You get the odd straight scene which both my guy and I would enjoy, mostly amateur rather than the over-produced stuff.
And you could also say I have an indirect interest in str8 sex: Men often make more sense to me in the way they enjoy their own sexuality whether they're straight or gay, even if we don't have the same sexual lifestyle. I get guys. I'm attracted to guys. I understand guys. Other men and their experiences intrigue me. And since a lot of guys seem to enjoy heterosexuality, it fascinates me because it reveals something about their guy-ness.
It makes a great fantasy to think of joining in with a straight or bi couple. But i would be completely distracted by his presence, his reactions, what he's getting out of it, how he explores the moment. Even if he gave me a hands-on guided tour of a woman, I think I would inevitably end up focussing on what it showed me about his experience. If many men are heterosexual, it's just another way to learn about the male experience.
So in a non-monogamous alternate universe maybe it could happen, and I'm sure it would reveal another side of men that I don't find obvious or intuitive, and which seems like a mystery to me even if I'm curious about it. But I don't know exactly what that scenario does for the woman involved. I imagine that it could be fairly boring for her.