I posted a thread here
a while back fishing for anyone with a similar experience to mine and didn't come up with anything. People on this forum talk about being "wired poly" or "wired mono" quite frequently. Well, I was DEFINITELY "wired" mono, but presently feel like I could never be happy go back to being monogamous again.
I was extremely content as a monogamous person, I had very very strong romantic notions about happily ever after with the one perfect person for me. I was into my 30s and had never cheated on anyone, and found myself easily able to focus all of my attention on one woman. And absolutely everything about monogamy made sense to me at the point when I met H.
And then she was polyamorous. And then all of these cool people she knew were polyamorous. And they seemed like they were having so much fun and I wasn't. And I just fell so deep in love with her that I was willing to consider any crazy idea that might let us be together forever. And this little nagging voice started suggesting that I maybe give it a try. And that snowball started picking up momentum, and more momentum, until I find myself at a point where I can remember how fiercely monogamous I used to be, but I can't really relate to why I used to be that way. It feels like a lifetime ago even though it's only been about 6 years.
Anyway... monogamous and polyamorous are two absolutely beautiful ways to be a human being. I know in my bones that under the right circumstances relationships between monogamous and polyamorous people can be as beautiful and long-lived as any other, and I wish you all the best on your journey however your relationship unfolds.