Whether she gets her own place or lives with OM is irrelevant. You sit there horrified, shocked and surprised at her every on of her actions. This is what cheating, WAWs or WAHs do: they act selfishly, they hurt people, they break families apart. My ex would bring the OM to our home to meet my children when I was away at work. This is what they do. Get used to it.
South -- things can get much worse than they are now. They will if you don't take action to protect your kids. Compared to some of the other people on these boards, your situation is relatively cut and dry. You have a tactical advantage of your wife moving out and offering you the family home. Imagine your wife seeing the OM while living with you and her asking you to leave the house so she can raise the kids with the OM. Lot's of people have had to face that on these boards. I've seen guys on these boards lose their wife, children and home to the OM. I have a good friend who only sees his children during the summers because his wife raises his children with the OM in another state. So however bad your situation is -- and I hate to say this -- you have it easier than many.
She is going to have to navigate her own relationship with your kids, mostly the 18 yr old now.
You job is to protect them as much as you can, especially your 12 yr old girl. You do that by giving them a stable home with the sane parent.
Your wife is showing them "crazy". Now you show them what sane looks like.
Get full possession of the house, go see a lawyer.
