Ignorance caused by sexual preference

I remember seeing a (terrible) scene from a tv-show once, where two homosexual men were going to try out having intercourse with a woman as some kind of curious experiment.
Now, I already find that a tremendous waste of the woman's time, but the dumb experiment itself isn't what I want to discuss:
A comment from one the guys pissed me off so badly, you wouldn't believe. It made the audience laugh, though, so I guess it just hit me at the wrong spot.

Besides having intercourse with a woman, they were also asked a few basic questions THAT EVERY SINGLE PERSON WHO EVER HAD AN EDUCATION SHOULD KNOW about the female body and such. When the question was asked if he knew what a "vagina" was, he replied "yeah, I know it's the thing women pee with, but that's it", as if he was the authority on it. And he backed up his statement by pulling a concerned face, as the thought of filthy vagina was too much for him.

No, sir, your thing is the thing you pee with. Women actually have a seperate hole for that shit, so keep your concerned face to yourself and go back to school.

Maybe it's not so much that I felt it was insulting towards women, even though there seems to be an odd trend going on between certain gay men to find the female crotch the most disgusting thing ever; while they stick the thing, which with they do what women are claimed to do with their genetalia, in a hole that isn't any more sanitary. I just don't get that.
But I think I felt angry because the guy was just so damn stupid. You learn about the male and female body at school; how dare you be that stupid.
Being homosexual shouldn't give you a free card to know nothing about women.

But, heterosexuals are often just as annoyingly stupid. While we don't learn about homosexuality in school, the ignorant thought that every homosexual gives blowjobs or has a shit fetish is very much alive and just as insulting.
We need to stop thinking the worst about each other.