Don't leave your kids behind. Can't you take them with you? You said she was pretty much neglecting them, so they need you more than ever.
In the meantime, conduct yourself as though you have separated emotionally from her and this inappropriate job. Otherwise, it will appear as if you condone it. However, I don't think you should be the one isolated in your room. At times, you may need to go there, to regain control over emotions, or whatever. Spend time with the kids after dinner, helpIng with homework or playing with them. You can be their bright spot of the day.
You can separate the bills so that she is responsible for half. Get your name off any crdit cards or accounts she uses. Also, separating your bank accounts, etc. Some men even have to protect their savings and retirement fund, or their kids'' college fund.
What I am saying, Joe, is if you just cannot take the kids and leave at this time, then do everything possible to show her you are enforcing your boundary of not accepting an open M, if that is what you told her.
Protect your little kids as best you can. Her son may start to ask questions, and you should not have to lie to cover what she's doing. But that is my opinion and some will not agree. That is something you have to decide.
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!
