When I Became The Dominant Partner Unexpectedly

I've been in a long-term relationship with my partner for six years. It started out as very traditional, dating, then moving in together after a year. We had our ups and downs but always talked things through. For the past couple of years though, we’ve explored different facets of intimacy. She’s become more interested in kink and BDSM, which I was initially hesitant about because it wasn't something that naturally appealed to me much before. Over time, as she learned more about her desires, she started sharing them with me. We agreed on some ground rules and boundaries, but mostly, we stuck to light teasing and play scenarios where control switched between us or she played out fantasies for my amusement. I was never into being submissive, though, it felt uncomfortable and unnatural. Recently, something shifted. During a particularly intense session where she wanted to push our boundaries slightly further, it wasn't about me giving her orders or having power over her anymore; instead, she seemed excited when I took on that role naturally in the moment without even planning it beforehand. It was surprising for both of us how smoothly and easily it flowed, with no resentment or tension from either side. Afterwards, we sat down to talk about what had just happened because it felt significant. Both agreed that while we didn't force anything or break any rules, we simply followed the natural direction of our desires in that moment. Now here’s where I need some perspective: do you think I should pursue more activities as this dominant side of us now, or keep things balanced with shared control? Am I crossing a line by enjoying it when she's submissive to me if she didn't initiate those dynamics?