Thanks to the administrators who allowed me to reopen this thread.
Quick summary: my daughter, who lives on the other side of the country, left her husband of 3 years (no children). She'd gotten involved with a co-worker. The co-worker, married with two toddlers, left his spouse as well. They've both moved out of the marriage homes, but are not cohabiting. The co-workers spouse is being "great" (their word) about it, even attending the same social events with them, driving them to the airport, and cooperating with child-duties.
Daughter and co-worker are still working together. They recently disclosed their relationship to their agency (non-profit, social-services), and so far no negative consequences. The two of them came to the east to attend a wedding (his friend) and to spend a week with family (my family-cousins and aunt and uncle).
When she told me of this plan, I told her it made me uncomfortable. First of all, this triggers my old infidelity traumas. Neither of them are officially divorced. Going on a cross-country trip to attend a wedding and introduce your bf to your family is the sort of thing you do when you have found Mr. Right. This seems too soon, I told her. She demurred, saying it wasn't like that between them, it was just convenient to travel together. No worries, dad!
But, when she got here, she kept asking me what I thought of him - and I kept giving polite, vague answers. I felt bad for the guy actually, being thrust into a family gathering with it's own dramas and "interesting personalities." The vibe she was giving out was - that this person is a significant boyfriend. The younger cousins all seemed to rally around the new bf. He's trans and many of my younger family members are LGTBQ, or strongly allied.
His life is a mess, right now. He's the main care-giver for the kids, and his ex is moving a couple of hours away for work soon. He doesn't have a stable living situation yet. He got a "tiny-house" but has no place to put it, yet. He may move it to a farm, but will have to set up plumbing, power, etc for it.
My strongest objection to his is that he's a cheater. And we all know cheaters will cheat again. She can't trust him, and he can't trust her. I've lost trust in her as well.
I got more of my daughter's back-story. She'd been trying with the ex to have a baby for over a year, with no success, and was growing increasingly upset with his avoidance. She'd seen a doctor about it who told her the place to start was with tests for her husband. The ex avoided going in for tests. She was upset with his lack of emotional engagement with her on the issue. When he finally got the tests, it turned out he had a low sperm count, for which there are corrective measures - which again he put off, she said.
This is not an excuse for having an affair. But, it explains that a rift between her and her husband came first. Especially painful for me because I'd been hoping for a grandchild, but since non had been forthcoming I assumed it was their choice and tried to reconcile with that - without mentioning it to them. but, now it seems my daughter very much wanted a child and now can't have one. It's too late, she feels. She's 36 and not likely to find husband/father material in the very near future.
If she stays with this bf, she'll be back in a situation she disliked and walked away from before she was married - tied to a town/region because her significant other had small children.
As for me, my plans are out the window. I was going to buy a house near her and settle down there. Now, her future is too unpredictable for me to do that, I feel.