My Secret Desire to Roleplay a Reluctant Victim

I've been in this relationship for three years now, and my partner, let's call her Mia, is wonderful. She's kind, supportive, and always makes me feel loved. We have a great sex life too, but lately there's something I've wanted to try that she doesn't share an interest in. I know it might sound disturbing to some, but I’ve found myself fascinated with the idea of being a reluctant participant. It’s not about non-consent, mind you, just the feeling of submission and helplessness in play scenarios. I started thinking about this more when we watched a film that included elements of control and reluctance as fantasy roleplay. I felt a rush that went straight to my core, but also felt ashamed because it wasn’t something Mia would want to explore with me. When I tried mentioning the concept lightly during one of our sex talks, she seemed uncomfortable and quickly steered the conversation elsewhere. I haven't told her this before because I don't want to make her feel pressured or bad about herself for not sharing my interests. But as much as I respect her boundaries, there are nights when the fantasies take over and all I can think about is wanting to experience it with someone who understands me, even if that means finding another partner temporarily. The fantasy itself is intense: being handcuffed by a dominant figure in our home during foreplay. The touch would be rough but controlled, leading into sex that’s more forceful than usual. In my mind, there's no actual danger involved; it’s purely about the thrill of feeling restrained and helpless. I’m conflicted because I care deeply for Mia, but at night when I'm alone, the fantasy only grows stronger. It feels like a part of me is lying to her just by not being honest about this desire. Do others in committed relationships explore these kinds of fantasies without their partner knowing? Am I an asshole for wanting something she’s uncomfortable with?