... Was I the Asshole? ...

I've been dating my partner, Alex, for about two years now. We're very compatible in most ways, similar interests, same goals, great sex life... but there's this one thing that nags at me like a splinter. It's not big or anything, just something I've never brought up because I'm scared it'll change things between us. You see, I have this kink, I love playing doctor. Not the gentle kind where I pretend to be the nurse and Alex takes care of me... nope, more like when I’m in charge and they’re the patient. It started a few months into our relationship; I had been hinting at it for a while but never outright saying anything because I didn't want to freak him out. He knows about it now, kind of, he said okay to being my plaything occasionally as long as he doesn’t have to go all in on the roleplaying part if he's not feeling it that day. So here’s where it gets messy. We were at this party last week and got a bit tipsy... I mean, really drunk, so we decided to head back to our place early for some fun. When we got home, I suggested we do something different, you know? Something exciting. So I started by checking Alex's temperature with an old-school mercury thermometer, the kind that goes up your butt, and once I had it in there... well, things escalated quickly from there. I'll spare the details about what exactly happened afterward, let’s just say I took full control of the situation. The only problem is, after a while Alex started to look uncomfortable and pulled away, saying they needed space. They didn't outright refuse me next time we talked, but... it was clear something felt off. I'm really worried now that what happened last week might have ruined everything between us, or at least made them unsure about our future together. I know there's no real way to tell if I fucked up or not unless Alex says so outright. But sometimes when I think back, the look on their face... it's haunting me. So here’s my question: Am I being an asshole for pushing a kink that makes my partner uncomfortable? Or is this just normal territory in a relationship where both parties are exploring each other's limits and boundaries? ...