What is happening you ask?
Seems like one big miserable cycle that's not likely to change.
Especially if there's been some physical abuse & if getting worse.
I think you know what's best for you & your children.

Thought I was protecting my son thru years of bad marriage that wasn't his real dad.
Big mistake on my part. As a 28 yr old he suffers from PTSD, won't go to counseling & can't understand why his girlfriend mistreats him... After 4 yrs he should have moved on but that's what he learned during those years with ex-h here. To stay together, it might get better. But things didn't get better in my home so that's what he learned, to stay & just take it. He even defends her...
I have guilt beyond words knowing how he has been affected.

Everyone's situation is different. Please stay safe. Kids reactions might not be so obvious now but as adults you want them to make healthy relationship choices.

I'm sure you're a wonderful mom so no offense intended. Just my personal experience. Wish you & girls the best. Health & happiness.

Take care.