It sounds like your son is caught in the "cylce of abuse" with this sociopath. It's very hard to break free.

If he seriously wants to be free he has to iniate a "no contact" rule with her. None. Nada. No texts, emails etc. He can block her numberr from his cell and change to different email account. He just has to see the light or he won't be able to do this. Thank God he didn' t marry her!! I'll be praying for you all .