Wrestling with Myself About Open Relationships...

So I'm in my late 20s and been in an open relationship for about a year now. My partner is really understanding, supportive of my growth as a person. But lately I've...well, let's just say things have gotten complicated. It started with one night when I was out at this bar, getting to know someone new. We hit it off and...let's just say there were some...physical intimacies that occurred. Not exactly casual hook-ups or anything explicit like that, I don't do that, but more of a shared emotional connection through physical touch. This person is really kind-hearted, empathetic even. She understands the nuances of open relationships better than I ever could. But after that one night, it feels...different now. More intense somehow? And every time we meet up since then, there's this lingering something that's hard to ignore. I've been trying my best not to think about it too much and just focus on my relationship. Maybe I'm overthinking everything...or maybe I need to confront how these feelings are shifting things for me. It's confusing though because at the same time, I still care deeply for who I am with now, she's amazing too. So here's where it gets tricky: my partner and this other person recently agreed that they should have a 'talk' about their boundaries in this open relationship setup. And then...I was invited to join them for the discussion. As someone who usually likes clear lines, suddenly I don't know what side of the line I'm supposed to stand on anymore. Does any of this make sense? It feels like every time I try to understand my feelings, another emotion comes up and scrambles it all over again. Maybe one day I'll figure out where my head is at...until then, just wrestling with myself about what kind of relationship, or relationships, I want moving forward.