DONT DO IT LADDIE!!! THEY ARE IN CAHOOTS TOGETHER!!!!
No seriously are you sure you are not confused with MY MIL?!? LOL
That is the ultimate manipulation. That is horrible for her to ask you to take him back. It's frankly none of her business anyway. She sounds like she needs to let her baby grow up and own up to his own decisions.
Sorry you had to go through that. But if you wan't my advice, I would distance yourself from you MIL. Don't answer the phone for a while. She will try and try again, and you know what is best, not her.
Go have a hot bath or foot scrub or something for your hard travels..
(((and hugs)))