Sounds like the issue with the phone is more about ow and her demands if there is other woman and not so much about him.

Sounds like pressure to me but not by you.

Only contact him if there is an issue with the kids and let him be.

The Bomb: 08/05
H moves out: 06/2006
H moves back: 01/07 & Out again: 01/07
H moves back: 03/08 & Out again: 04/08
H moves back: 05/09 & Out again: 07/09
Divorced 08-12
Kids: 22, 20, 19