Uh, Andrew. . .you’re not allowed to make assumptions on someone’s sexuality based on a picture in which you can’t even see her face at all. What if said gay man in your example assumed that you were gay before he kissed you? That’s about as much sense as it makes to assume that any woman you might happen to want to assault is a) straight and b) wants to be assaulted. And let’s don’t lie to ourselves: being kissed is like any other form of sexual behavior. Nice if you want it, terrible if you don’t.