I once asked a gay coworker if the thought of 'being with a woman' was as ooky to him as the thought of 'being with a guy' is for me. He said he thought probably so.
It's not simply a matter of having sex with someone you're not attracted to. Could I have an orgasm with a guy? Yeah, maybe (if there were no women left on the planet). It's a disgusting thought.
It’s disgusting to me to, but for some reason really tough guys who end up in jail often find the idea attractive enough to risk punishment for it.