I pray for your brother. It must be very hard on him.
But...he should try to keep the “marriage” together anyway, if possibe.
The kids will be a LOT better off with him IN the house, rather than her boyfriends.
He can’t keep the marriege together. He tried, he still loves her, she cheated on him again. What’s he supposed to do, be a chump for another 11 years until his youngest is 18? She made an active choice to destroy the family. How can you expect him to coexist in a house with her?
They will get divorced. he has told her in no uncertain terms that if she tries to get anything other than standard child support he will go for “blood”. This includes telling her employer what she did (the guy she’s banging is a subordinate to her at her job) This will get her fired. They will drain all their savings getting lawyers for the court battle, etc, etc. Who suffers? Yeah the kids.
He doesn’t want to do this. Why does the guy always have to be the chump? She should friggin’ move out. It’s her fault. Yet he’s stuck, doing the best he can, surpressing anger and resentment, trying his hardest for his boys. It’s just horrible.