Caught in a Moment of Vulnerability

I've been with my partner for five years now. We met during university, both a bit naive and very much in love. Our relationship has always had its ups and downs, but it's never lacked passion or intimacy until recently. Over the past few months, I’ve found myself drawn to an aspect of sex play that’s not something we've explored together, specifically role-playing scenarios involving dominant-submissive dynamics. It started with reading books and watching videos, which led me to start daydreaming about it. The idea of surrendering control in a sexual context feels exciting and exhilarating, but I know my partner isn't interested in that type of play. He’s always been more traditional in his approach and doesn’t see the appeal in power exchange roles. This week, I hit a low point. Stressed from work and feeling disconnected emotionally with my partner, I made an impulsive decision to join a local BDSM club for one night, just as a way to experience these fantasies firsthand without bringing them into our relationship. I didn't tell him because I was scared of his reaction. The moment felt liberating yet terrifying at the same time, I participated in some light role-play and bondage activities with strangers who were also new to this kind of exploration. Afterward, there was a sense of relief but also guilt knowing that what I did wasn’t just about my desires; it was an act of rebellion against our relationship’s limitations. Yesterday, I found myself unable to hide the truth any longer. We had another one of those tense conversations where we were both being honest and vulnerable with each other, and finally, everything came out. He was shocked and hurt, but surprisingly open to discussing it rather than immediately dismissing my interests as wrong or unhealthy. Now, I’m at a crossroads. Am I cheating by going behind his back even if there's no emotional attachment involved? Is what I did necessary for me to maintain my mental health and relationship satisfaction? How do other couples navigate these kinds of boundaries without losing each other in the process?