Magnetism

So today my instructor was going on about magnetic induction, and one of his analogies was: "Usually guys are attracted to girls, and vice versa. Think of the north pole as a guy and the south pole as a girl. Now if a guy comes up and hits on the other guy, he gets punched. And if a girl hits on the other girl she gets slapped." What followed was a fairly large session of gay bashing by the rest of the class. No one knows im gay, and I definately didn't let on to it. I guess I was a little bothered by it though. It's one thing when my close friends call me a fag, they know I am one, and I know they're just joking around. I guess when it's someone who doesn't know I'm gay, it's just kind of insulting.