No, I don't feel that way and do enjoy straight romances too. (When they're well done, anyway. Like any other romance.) I don't think this makes you a terrible person, but I don't understand why any relationship would feel less valid or real because of the characters genders, ...I guess it's just one of those things you can't explain. As long as you aren't dicks to other people over it I suppose it's fine? At least you realize it's a thing.