If the WW is in an A, she's going to want the LBH to be her BFF.......while she plays house with OM. The mistake LBH's make is thinking they can become a wayward W's buddy and thereby slowly working their relationship around to being more than friends. Some guys think they will wait around being the wayward W's pal and when OM plans fall through......then good ole hubby will be standing with his arms wide open for the return of his W. He hasn't changed her mind or caused her to fall for him, rather than OM. It is Plan B, at its finest. I have seen H's who thought they could play the nice guy friend until OM messed up and yada, yada, yada. The H does not become Plan A by being the WW's BFF.
The LBH and the WW view their "friendship" differently. He sees it as a vehicle to progress their relationship into more than just friends. Did you notice where I said she wants the LBH to be her BFF? Trust me, it is the selfish thinking of a WW, and she will manipulate it for all it's worth. It won't take long for the H to realize it is a one-sided "friendship" and she is simply using him.
Why did the uncle's WW react the way she did when uncle found a new GF? The WW does not want her position of control with the LBH to be replaced or threatened by another woman who will influence (maybe manipulate) him more than she can. As long as WW and uncle are legally M, then uncle and GF won't M, and WW still has leverage on the control strings. IDK why uncle hasn't M the GF, but my guess is that he is benefiting, too. Maybe everyone is benefiting from the setup, IDK. But I have learned everything is not always as it appears on the surface......especially when you have two women with a man in the middle.
If the uncle's WW is good friends with your W, then it is very possible she thinks this could work with Phoenix, her, and OM. (Guess you are wondering why I didn't say this at first, and leave off the rest).
I want to make something clear if I can. There is a difference in being friend-ly, and being BFF's. When the sh't hit the fan at my place, I said something along the same lines that other WW's say about how they hope they can always remain friends. My H just slowly shook his head, look dead in my eyes, and told me we would never be friends if I left him. Now, gentlemen.....as you may imagine, it takes a lot to shock me speechless, but that did it. Oh, the arrogance of a WW!
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!