Dear, dear me. What a carry on. Her, that is. No wonder he's a lying, cheating, entitled rodent with a mother like that. That#s not to excuse him, he's an adult.
really, stop listening to his, and her, complete shit. Block him, block her. The truth is looking them both in the face and they don't like it. Too bad, there are kids here.
You have been admirably dignified. Please, stop expecting them to be decent people. They have amply illustrated they are nothing of the sort and, probably, never will be. I dread to think what your marriage was like if he's capable of this highly manipulative rubbish - all the best to the ow (not).
Stop engaging with them both. Keep comms with him to the bare bones minimum, businesslike. He's not your friend. Goes without saying neither is she - who is she anyway? She's nothing in this, it's between you and your adult husband, stbx (thank goodness).
dust yourself off, you have the chance of a decent life now. Stop letting these spoilt children in adult bodies affect how you feel about yourself xx