Trying to Understand My Kink

I've been playing as Mommy for a few months now. It's strange, really, I'm usually so level-headed and rational about everything. But being the disciplinarian in these scenes with my partner feels oddly satisfying. Is it because it lets me explore a side of myself that's always been there but hidden? Or is it just another form of power play? When I spank him or make him wear those little boy pajamas, he looks so submissive and vulnerable. It's not the physical act itself that turns me on, though, it’s watching how he reacts to my authority. Why does this turn me on when other things don't? What am I really getting out of being Mommy?