Not So Secret Fantasies

I've been keeping something from my wife for months now. It's this dark little fantasy I have where I'm the submissive one in a relationship, even though I am usually so domineering and take control. I always thought she would be disappointed or upset if she knew, but maybe it's okay to let go sometimes? We're both 18+ adults and everything is consensual, of course. I feel ashamed for not being as open with her as I should be, but also excited about the idea of exploring something new together. It's weird how this can make me feel so vulnerable yet turned on at the same time. Maybe it's just a phase or maybe it'll change our relationship forever if we talk about it properly.