After thinking about your sitch a bit, I can now see that W clearly sees you as a friend. Not H.
If you really want to save your M, it's high time that you really pull back and stop being so available/helpful to W. We see this quite bit where the WAW slowly replaces the OM in the H's place as a father. This is where you really need to put W in her place and tell her in no uncertain terms that you are their father.
I am all for respectful and cordial exchanges when it comes to children. The problem I am seeing right now is that your W has given no thought to the consequences of her choices of abdicating her responsibilities as a wife. Yeah, her position at her company is her responsibility and I do see her sobering up after realizing what precarious position she put herself with her boozy/partying antics with her colleagues at the company. She pulled back because she knows that she was skating on thin ice as an employee. The unspoken threat is hanging over head and she knows it. Very much does know this knife could come down at anytime.
With you, W does not feel that she's not skating on thin ice in the marital department. Why should she given that you and W are so friendly? There's no perceived threat of loss given that you two are so chummy. Haven't you gotten any sense of that from reading HPoriot's threads? This is textbook case of the W knowing full well what happens if she continues with the OM--loss of HP, loss of S11, and loss of the happy family unit. And frankly many, many sitches have turned around when the W or H senses losing their spouses forever--for real. In fact, many times it happend literally at the 11th hour.
Have you communicated in any way to W that you do not want a S nor a divorce?
