It's Not Who I Am But Still...

I've been with my partner for three years now and we're generally pretty happy. We do a lot of the same things, but lately there's this thing that has me really conflicted. It started off small, like watching those bondage videos together. At first it felt silly, like playing dress-up, but then... I don't know, it got more serious. Now every once in a while, when we're alone and feeling adventurous, I start thinking about these things. I'll ask them to tie me up or blindfold me, just for a moment. It's not who I am normally; I like to feel free and in control. But something about being restrained, even if it's just lightly, turns me on more than I'd ever expected. I don't want anyone else to know this side of myself. I almost didn't tell you either, but I needed someone to hear what I'm going through. It's weird because the rest of my life is normal, work, friends, family. And with my partner too it's all good and easy-going most days. But there's just this one thing that feels wrong somehow... Should I be ashamed? It can't be a bad thing if we both agree to it, right? I guess what I'm asking is, how do I reconcile feeling this way while still being true to who I am outside of these moments? It’s confusing and makes me feel like maybe there's something wrong with me.