This is my first post on your thread, but I have spent several hours over the last few days reading your "cake eating" threads - ALL 15 OF THEM! Maybe I'm the only one to have done that - giving me quite the unique perspective! I'll say first off that I never understood the whole fascination with soap operas - but what I have read in 150 or so pages of posts about your situation is just unreal.
A few brief observations because I don't have much time to write unfortunately. Your XH has completely detached from reality. Whether it is something neurological, or MLC, or whatever - the reality is that whoever you married no longer exists.
Also, being two years out from BD, I worry for your continued inability to detach as well, especially from the OW. She has a huge influence on you. Is there any way to just decide to let go of her? Maybe imagine scenarios where you might see her (the concerts, supermarket, etc.) and then pre-decide in your mind how you will handle that if it occurs? You sound very classy - but your interactions with her are definitely, to use one of your old illustrations, Jerry Springer.
I say this for you. I want you to be No Longer Wretched, even when the buttons are pushed.
The most recent development, the weekly dinner as a family "proposal" from XH - be careful. There is a good chance it is a mixture of manipulation and just his own selfish needs. Manipulation - I will bet that some of what could come out in court regarding his handling of financial situations could bring about severe legal consequences for him. Selfish Needs - every day with the OW will increasingly show him that his unhappiness was not your fault. There is an emptiness that nothing will fill. He is returning to the family, partially to try and fill that. Unfortunately, that is a lot of pressure. A wife and kids cannot be the only source of happiness for a H. It has to come from within. And that doesn't exist for your XH.
Until he shows some kind of personal growth or major change (not just coming around again once a week), I would continue to NC him with some major boundaries.
Another Stander and Bustorama (as well as Brooklyn and labug) have given you great advice these two years. I am new here, so that's all I will say for now. Except for one more thing - one thing I am learning is that DBing is something we do even if the M fails. It is designed to help us continue our lives in a greater way than we lived them before, without or with our WAS's. Your XH is am,ost certainly deranged half the time - but I'm sure there are still those 180s you can make to better yourself.
You are one of the unsung heroes of the world. You didn't ask to be - but reading your situation has given me motivation to keep DBing, to keep 180ing, and to keep going. Keep it up!
_________________________ Me: 37 W: 37 M: 11 D:5 S:2 IDLYA, W removed rings, BD 07/13 EA/Fantasy (PA?) confirmed 12/13 W moved out 05/14