My younger sister is a lesbian. I was surprised to learn that a female friend that stayed with our family during a college break, tried to forcibly take advantage of her. By all accounts this POS identifies as a straight woman. Then of course there are the pervy straight men who believe conversion sex is actually a thing. My sister's partner says she works with quite a few straight women who also believe that she just hasn't found the right penis yet. But to her face they try to pass themselves off as a shining example of an LGBT ally.
The flip side to this is that there are a lot of gay people, both men and women, who will sleep with the opposite sex if they are desperate and horny enough. I've been to plenty of gay bars and I've heard quite a few of them say that it's easy, no strings attached sex. They claim it doesn't impact their sexual preference. They will still end up with a same-sex partner. I couldn't do something like that and I know my sister couldn't either. But to each their own.