All I know is I can't help being attracted to women. You can talk to me all day about the merits of sucking dick and show me an infinite amount of naked dudes, my dick won't get hard unless I'm staring at a beautiful woman.
No dude fucks another dude because they feel like spicing things up a bit in their sex life.
I don't know how it is to be gay, but my feeling is they legitimately feel the same way about the same sex. I'm fine with that.