If you don't want your kids to talk to him, then you need to establish some boundaries. You haven't done that yet.
That's not even the right thing to do. I shouldn't involve the kids. They should be loved by anyone who wants to.
M35 XW34 D5 D4 M 6years T 10years Bomb 5/2013 Joint Petition signed 6/2013 Moved out end of 8/2013 Court Hearing of Joint Petition 9/2013 D finalized in 3 months - no news yet