A Clinical Encounter

I'm in my early 30s and have been in an open relationship for over a year now. My partner is supportive of me exploring different connections and recently introduced me to someone she thinks I'd really click with sexually. This person, Alex, is about the same age as us and has a background in kink and BDSM that intrigues me. We met up at his place last weekend for our first session together. After some initial conversation and getting comfortable, we moved on to a more explicit discussion of what each of us wanted and were into. He explained how he likes to incorporate bondage elements and has experience with impact play. We agreed to start relatively mild but also pushed enough to explore boundaries. I was blindfolded and tied up on his bed. Alex proceeded with light spanking, gradually increasing the intensity while checking in constantly about my pleasure levels. The sensation built as I felt him unbuttoning my clothes. Soon, he started rubbing me through my underwear and undressed me fully. With his hands and a few toys, we moved into deep penetration and intense stimulation for several minutes until I was close to climax. He slowed down then teased the edge of orgasm back and forth until finally letting me go over the brink. Afterwards, we had a frank conversation about what felt good and what didn't so we could continue exploring together. It left me wondering how much further into kink territory I might be willing to venture. Anyone else ever have an adventurous sexual experience that expanded your horizons? How far would you go?