Your submissiveness might be coming out so strongly because you've found someone who doesn't seem judgmental about it. Not that your boyfriend necessarily is judgmental, but if he doesn't share your interest that can have a stifling effect. Especially, I will say, for someone who's submissive, because if part of your pleasure is pleasing someone else, then if this doesn't please him, you're not really invited to feel that way, are you? Just in your head, of course, but finding someone more amenable might be a big relief.