It's up to him what he likes and you shouldn't judge him because of it - doesn't change the person you became friends with after all! On the other hand, you are completely entitled to choose your friends, even if you decide to do it with such irrelevant / judgemental criteria.
There's nothing wrong with the fact that this creeps you out - nothing you can do about that - but if you let it change the way you treat this guy or let it affect your friendship with him, then I'd say there's something wrong.