As far as I am concerned, the father can go straight to hell.
He was told by members of both bio parents families that this was going on. BOTH sides. Usually, you might see one side accuse while the other defends- but both sides made these claims to him, and he ignored them. Cut off his own family from seeing him.
So, in my eyes, he belongs in the male ward of that jail for allowing those two children to be in her presence. Did he not love and care enough about his son to ask him privately if that ***** was hurting him? He enabled the step monster.
God have mercy on both of their souls, because I sure as hell won't!