I would write him an email stating how much he owes you in back CS and request that when he gets his UI he pays it. If he doesn't then you have a record that you tried to be cordial and he chose for that money to go somewhere else.

I really think that the nice thing isn't going to work with your H. He knows he is in trouble with the cs, but doesn't think you will ever do anything about it so he will carry on this way. I hardly think he is going to wake up one day and tell himself to be a stand up guy and pay his cs to you. He will need to be forced by a judge.

Me: 46 FWS: 36
Married and Divorced 4/07, Pregnant 7/07,False R 7/07
Baby Girl born 3/08
Kicked him out because OW: 7/08
5/10 He realized what he had and lost.
Moved home! REMARRIED 3/14/11!!