May - came by to read your thread, since you had posted on mine. You have a huge collective of ppl here that are saying basically the same thing - he has to go. We have similar situations...I totally get the difficulty of doing asking him to leave...and, on the flip side, understand the difficulty of having them in the house. The difference being my H would leave the house to be with his OW, three plus nights a week and that will tear your heart out.
What both of our H's have not experienced is the loss of us and family. They don't know what they will miss because they haven't had to do without us. Though we are in-house with them trying to DB, they still have access to us, and easily manipulate us. And with the kids around, things just move along and before you know it, your lax on the DB front.
Our husbands seem to share the jerk, arrogant, narcissistic gene - what mine told me was that he knew it was time to end it long ago, and I think only until he felt me dropping the rope - it was the push he needed to drop her. Its only been a week, but I am extremely wary/suspicious of everything - trying to learn from your situation - to keep up DB efforts to avoid backsliding.
For how hard I hung on to him thru these past months to stay in the house - I know EXACTLY what you feel - but - you will destroy any legitimate stand you have in your marriage if you don't send him packing (did I just say that? please be sure to tell me the same thing when/if my H goes back to the OW). If he won't leave, file D, and the judicial system will weigh in on his exit.
For our weak minded husbands, this might be the jolt he needs to drop her - because if yours is anything like mine, he thinks YOUR weak and will take advantage of you as much as he can so he can enjoy his side adventure.
M:50 H:49 D:16 S:13 M:23 T:25 BD: Feb 25th 2020 EA/PA: Dec 2019 - June 11, 2020 Behind every broken woman is a broken man...