I think a lot of straight people would, however, feel a degree of repulsion towards the idea of kissing and having sex with someone of the their non preferred-s

I think a lot of straight people would, however, feel a degree of repulsion towards the idea of kissing and having sex with someone of the their non preferred-sex. A consideration which, due to culturally norms, is probably pushed into the heads of gay people. Anecdotally I think most of my gay friends have commented on how gross vaginas are to them. Add whatever clarifications on fluidity and spectrums that you want....