I would just ignore the calls unless they are an emergency... tell him this is divorce, get used to it... and tune him out.
I suspect he wants to try divorce and STILL be good friends with you... I would make it clear you don`t want to be friends with someone who does what he`s been doing... and minimize contact and ask your friends to keep him out of the loop if they don`t mind... he`s SPYING on you otherwise... if he wants a divorce he needs to stop sending texts and checking up on you through third parties...
Teach him what divorce is, don`t sugar coat it for him.