Your saying all the right things so I’m assuming your battling with yourself almost want one of us to tell you something different. That’s not a dig your in an awful situation we all know it we have been there some still are.
He shouldn’t be doing it in the house where your son and you know your in for even worse ride of sons dad finds out or worse social services. I went through that and it was awful, I felt attacked by them I was doing my best trying to help everyone with no support at all. I wouldn’t wish that on you.
Maybe it will be his wake up call or maybe it will be yours to finish with him. Only you can make the decision.