Thing is, I know she doesn't trust him deep down. They have had arguments about her checking his phone, why he has his stuff locked up like Ft. Knox etc.
Also, I have never said one cross word about him to her or him. So there isn't any history that he could say would be typical "messy" behavior.
I think the denial would come from not wanting to start over, take the kids away from him, untangle their bills etc. The typical stuff we do to rationalize staying in a troubled relationship.
As for proof, I have it and my thought was to send it anonymously bc of many of the reasons stated. I just don't think I could live with the fact that I knew and stood idle.
Trust me, I have prayed and prayed for guidance on this so it certainly isn't coming from a messy place.