New to ENM here. So bear in mind I am still breaking through that monogamous programming.

So within the past 2 months I have begun seeing a new guy, whom already has a primary partner, but is ENM. What we initially started as “I’m ENM lets try being FWB” I feel has quickly progressed into us actually highly enjoying each other…,what start as 7:30 at home dinner plans turning into being up late hanging out in bed w this person until 1am. He lives around the corner from me so it makes things all too easy to see each other. It makes it all too easy for quick late night sneaks into bed and hangs (no sleepovers allowed). We have (somehow) managed to see each other 3 times already since this past weekend. He obviously treats me w the respect one would treat any friend, but there is definitely a tinge of “feelings,” I think are arising between us. I am not going off of blatantly direct things he has told me, but rather small hints and gesture/expressions he has made around me, such as “I never thought we’d both enjoy each other so much,” doing sweet affectionate things beyond simply just being sexual, though I am aware my interpretation could be skewed/interpreting it as more than what it is.. I am a businessownerr and he just started his own business w his partner this past year, that I know will have him verrrry busy here shortly, if not, already. However, He still makes great efforts to see me regularly. The thought of that change (seeing each other much less) still scares/upsets me, as much as I know it’s impending, and that the whole point of this ENM thing is enjoying the present moment and connection I have w this person, and that change is inevitable.

Anyway, I come here to ask, it is necessarily “bad” that I may be developing feelings for this person? (I’m honestly not even sure if it’s feelings or simply I’m super into this person and the NRE is so strong right now, it’s like a high and it’s so nice, I am just so highly enjoying this journey/chapter w this person.) I am still casually seeing other people, am at a really good place in life, highly enjoying that freedom of being able to do so and don’t want to change that, yet at the same time, I of course am having sex w this one and have had a few very intimate moments w him recently, (ie: bringing up my fears of him possibly pursing one of my friends, which he assured me won’t happen cause he really enjoys what we have together currently) which I thing also adds to the “am I developing feelings w this person?” I fantasize about our sex and think about him/text each other throughout the day. Which I suppose just comes w the territory of ENM??

Though my fear, I just can’t seem to shake the comment a friend of mine made when I informed her (excitedly) I was seeing someone already in a relationship (She is not ENM, btw). I think she was just looking out for me but she really scared the shit out of me when she said “he has a partner he can run back to if/when things don’t work out between you guys, and you will just be alone. At the end of the day, he has that emotional support/investment w someone, and you don’t have that w him. You have to take that into consideration.” And so now I sacred because I am really excited in this NRE that I feel is really developing into something, (even he himself has made hints to, too) yet because he already has a partner, (they’re only ENM, not poly, but not closed off to it) I fear that I may be just blowing things up in my head and maybe there isn’t actually feelings there at all, am I hurting myself by allowing myself to develop feelings/connection w this person?? Am I hurting myself by risking potentially being left high and dry in the end of things go sour? Or is that just part of the game we play when we do ENM, part of the risks we take?

Tl,dr: I am seeing someone new (ENM) who already has a primary partner, (I do not) and I feel we may be developing feelings for each other, which terrifies me, and I’m not sure if it’s safe to allow myself to develop these feelings... Will I be left high and dry in the end? Or is becoming a bit vulnerable and allowing yourself to potentially developing feelings, part of the game we play, the risks we take? Or should I be trying to tone them down and keep myself “in check”, emotionally ??