His spew is projection. He doesn't feel good about himself and he is unable to connect the dots at this time because of his fog and confusion. He is lashing out at the person that was closest to him because he needs someone to blame and to justify his actions.
Sweetie, your boys know the truth, you know the truth. As you detach more you will be able to step back and not take his BS so personally. You will begin to connect the dots for yourself.
You're doing the right thing for your sons by just being there as support and filling in the gaps left by their father. Your boys may start hurling truth darts your H's way. At some point your H will realize that what is coming out of your kid's mouths are their feelings and not your words.
GM, you have choices here. It's your choice not to let your H's spew get to you. It's your choice to not share negative feelings about your H with your boys. It's your choice what kind of life you want to make of it for yourself and kids. Go about it as though your H is never coming back. That way if/when your H runs to catch up, you will be in a place where you will be better than OK with whatever you decide to do. Be that letting him back into your life or taking a different path.
I promise that if you let it, this does get better. It's another one of the choices that the LBS gets to make.
