So...we met at a sex club over three years ago when she was there with her other partner. Neither of us had been to that event before. Neither of us were looking for anything more than a good time. But, as stupid as it sounds, given the location, I instantly fell for her and knew I had to speak to them. We hit it off (no intimacy that night). We met the next night at a different club (not planned as such, we'd both said we might be there). The chemistry was instant. We spent all evening together, chatted for hours, and we were intimate. We met again the next two nights. Since then, we became bf/gf very quickly. We have been engaged for a couple of years now. We've been to clubs together, and as a threesome with her other partner. We've played with strangers and do still do this sometimes.Next, your "ENM" status: do you mean swinging? Both polyamory and swinging are under the "ethical non-monogamy" umbrella. It sounds like you're comfortable with the "sport sex but no feelings" aspect of swinging, but not comfortable at all with your nesting partner's polyamory. You and she have done some swinging. Maybe you'd like her to do more of that with you, and focus less on dating on her own, one-on-one with others.
I do feel guilty flirting with randoms when she's there, as it has upset her on occasion. So I rein it in. But I miss the confidence boost and thrill of being desired by a stranger. I've never thought previously I could be poly, as I find it hard to understand the splitting of time/love etc., even though she's given me amazing examples and ways to think about it in our many conversations. But the more I learn about it, I think I'm somewhere in between mono and poly. I can separate sex with randoms/her with new partners as just a physical act and not be bothered, but when feelings are involved, I struggle with jealousy/envy/insecurity. I could see myself with an FWB, maybe a relationship, but I'm not certain. We've been talking about me exploring this.
I'm 100% on board with the ENM mindset of "no one person can be someone's everything," but it's the emotional side I have problems coping with, given my completely mono experience prior to meeting her.