I'm sad for your DS's hard time and yours but also glad his eyes and mind are open.
It's heart-wrenching to watch a child's pain.
DD is struggling with issues caused by our being abandoned by STBX and has trouble going with him but still gets blinded by the glitter and the big personality.
Like you, BlueBird, I can't safe her from the forces that be, that are outside the walls of our house and never thought it would be her own father. My mother is also very NPD and she is seeing this, too. It makes me sad.
Perv won't even be real at counseling or be real with problems. He lies to counselors and thinks it's dumb and everyone else has issues but him... and OW.
I have some neighbors I write about who are a few years ahead of us in D but still fight over their kids. It's interesting now to see the kids there-one 15 and one 9-make fun of the father and OW now, along with the mother.
The father lost his figure of authority with them after what he did and there is no respect for him, FWIW. I see this starting with our DD and it makes me sad for her to lose the KISA side of a parent.
I am told by him that I'm very strict and no fun, but you know, she tells me "I trust you, mom and feel safe around only you." And I find that with my father, as my mother eventually left him. She is very glittery but not continuous and we/I get leery of that.
Perv acts "crazy" when something isn't going his way and my mother does it, too. I am just coming off a confrontation with her because DD couldn't go visit her for as long as she wanted, so she (my mother) had a tantrum at me.
Sorry for my long post and hope it will get better.
A person is a person, no matter how small. -Dr. Suess
Perserverance and spirit have done wonders in all ages.