Okay, fine. Just so you know, you don't have to be a "third" or a "unicorn" and be shared by an established couple to practice solo polyamory. In fact, most solo poly people wouldn't try to date in a triad shape. They would date multiple people individually, of whatever sex/gender they preferred. Dating in a triad is the hardest way to be poly, and hardly anyone does it. There are tons of threads here, current ones as well as older ones, that show all the ways triads are almost always doomed to fail.
Generally, couples do post a lot seeking someone to "share," to "add to their relationship." But they are deluded because mainstream media, not to mention porn, often depicts threeway relationships and sex. Poly does not mean group dating or group sex. Poly means you, a single person, may carry on romantic relationships with multiple people, with everyone's consent. You would mostly be having one-on-one dates and sex.
You and Ken
You and Barbie
You and Midge
And so on...
Ken and Barbie don't need to be a couple who date you, SoloPolyAltGuy. It's better if they aren't. You would see Ken on Monday, Barbie on Wednesday and Midge on Saturday. These 3 partners of yours may never cross paths. Or they may meet briefly at your door as they come and go. Or if you want to, you might have a group date with Ken and Barbie, say, go to dinner or a concert, but then you'd go home with one or the other of them.
I date Pixi and Aries. Pixi dates me and Malachi. Aries dates me and Serena. Malachi doesn't date anyone besides Pixi. Serena, Aries' gf, is married to a man, and he has a gf of his own. We are in a poly network but there is no group sex, and any group dating is just like, friends going out and doing things, or having dinner together at home, watching TV or whatever.
Here is our resource list. I recommend starting with the book
Opening Up, and/or the podcast
Multiamory.
