Node-o-rama

Sorry if this is an overly-personal topic; feel free to delete it if it is inappropriate.

I wonder if anyone here has seen or noticed any indicators in charts for open relationships or polyamorous inclination. Astrologically, my questions about it are: is it "hardwired" in the natal in some manner? Brought about by transit or progression? Or present in the relationship charts of the parties involved? Also, other than the obvious (Venus + Uranus I'd guess), what planets/signs would be significators?

Background behind this question: several years ago, when I was married to my ex-wife (with whom I was previously and currently friends) and in a period of lack of closeness with her, I happened to meet someone with whom I immediately fell in love. This was before I knew anything about astrology, and Neptune happened to be transiting opposite my Venus/MC at the time. The affair was strongly emotional but we never became physically involved, and in retrospect mostly a mistake on my part. I say "mostly" a mistake because it *was* a genuinely close connection for both of us - her moon and N.Node happen to be conjunct my Venus, so she was getting the same Neptune opposition, and it has always just felt very right between us.

The emotional affair wasn't the only factor in ending my marriage to my ex, but it was certainly a major one. We managed to make up and save our friendship, and since we have two kids together who we both dearly love (she and I are both Leos, which was also part of the marital struggle!), we work together closely with parenting issues and sharing joint custody. The kids are happy because they have a bigger extended family than most, and they don't have to worry about the usual strife that often afflicts kids in divorce situations. However, because all the craziness between my ex and I happened during their formative years, it has caused some issues, which we are all working together to heal and work through.

After my ex and I split, I entered another relationship that didn't work out. The woman I had fallen in love with was involved with someone else at the time, and I lacked patience to wait for her. We were still in love though, and we maintained frequent contact. She has always said that she is fiercely monogamous and resented me being with anyone else but her. I never thought much at all about the issue of my "relationship orientation", until the bare fact presented itself to me: I was very much in love with two people at once. Whether the practical side would ever work out was (and is) unknown to me; but the reality of my experience was of being polyamorous.

While in the ill-fated rebound relationship, my amour said "wait for me next time". And I tried, and failed. She was busy, involved, reclusive, elusive, etc. And about that time was when I met my current wife, with whom I am very much in love. But here's where it gets interesting. Current wife was polyamorous when she was younger, prior to living in a monastery for many years. She has known about my other love since the beginning, and was somewhat jealous at first but is now accepting of it (she is a triple-Gemini and is very changeable to say the least!). We have an open relationship in theory, though not in practice, and she honestly is perfectly happy with that fact, from everything I can tell (unless I'm totally missing something about the Gemini psychology - a few people who know of our situation have said that she probably is just afraid of losing me and is trying to use a sort of reversal-trick to keep me, but she gets indignant at that suggestion). So now, after revealing this to my old flame, she accused me of "wanting to have my cake and eat it too" and "wanting to play with the toy that mom won't let you have". Ok, to be fair, maybe so. That's certainly not my perspective and experience of it, but... whatever. (She is a Taurus btw).

So... do you think that the years-ago Neptune transit could be to blame for some of this mess? I feel very guiltily-responsible for complicating people's lives, and I don't like to cause hurt or frustration, though I have caused much, and am fervently working to rectify what I can. Anyway, I'm certainly not fishing for advice here, only astrological insight into the raw issue of polyamory and unconventional relationship modes. I'm only giving the nitty-gritty for context.