Was It Worth The Risk?

I've just broken up with my long-term girlfriend of five years. We were together since college and everything was fine until we started to drift apart emotionally over the last year or so. I found myself craving something different, but still in love with her in a way that kept me from ending things sooner. One night, after having a fight about how stuck our relationship felt, she left without saying much more than 'I need some space.' She didn't take any of her stuff and it seemed like maybe she was just feeling overwhelmed. We talked the next day over text messages but we both agreed to keep things as they were for now. A few days later, a friend set me up with someone I had been curious about online for months, let's call her Emma. She's really into DDLG stuff and I've always been intrigued by it but never had the courage to try. So here we are at this party where there was alcohol involved (which is probably part of why I agreed to go back to Emma's place)... I remember feeling nervous yet excited when she took my hand and led me up to her room. The bed was comfortable, her scent enveloped me as we talked about our interests over the next hour or so. Then came a moment where she suggested something playful, just pretend we're in different ages for fun. I mean, it's not like that’s real or anything. We started talking in baby talk and laughing at how silly it was to do. She held my hand firmly but gently as if guiding me somewhere safe. Soon enough, I found myself agreeing to be a bit more submissive than normal with her leading the way, just for fun and to explore something new together that night. I know this sounds risky now that I'm single again. But back then it felt liberating! We ended up having amazing experiences, pushing boundaries that my ex would never understand...but we also said it was only for tonight, no expectations after. That's why when I saw her later at another event and acted as if nothing happened between us, I still can't shake the feeling of being torn. How much should I regret having such a different experience now that my ex is gone? Did doing this make me the asshole here or was it just something we both needed to explore while alone? Am I an awful person for not wanting to go back to 'normal' even though things ended between us?