This is an interesting question. One of the things I've found fascinating about my love for femdom is that I'm not like most guys. I could get a hard on from seeing a naked girl, but it would be a boring and meaningless hard on. It would have no point, and I'd lose interest. What the girl does is actually MUCH more of a turn on than how she looks. Don't get me wrong. I love good looking girls, especially tall ones with some lean muscle and nice tits and not too skinny or fat, but it's nowhere near as important as what they do. For example, I would rather be with a fat girl who knows how to degrade me and hurt me than be with a beautiful girl who was into vanilla sex and treated me as an equal.
And about fettishes, if you're reffering to femdom and such, sex to me is out of the question if the girl is not 100% in charge. People call it close minded, but it's how I was born. I can't be the boss and I can't eb an equal partner. For me, femdom is an absolute necesity. True fact: I'd rather be with a domme that permanently denied me orgasms (assuming i could jerk off beyhind her back) than have to be with a girl who was a submissive, neutral or even switch.