Sorry that you are going through this
I love this statement from L
Sure, he has the 'right' to call. And you and your son have the 'right' to not answer the phone.
I wish I had learned that at a young age when my A father called, my A brother called and my XABF! But I know now and that is what is important!
Talk with your son and yes maybe get him to counseling or to Aateen meetings-In the end it will be beneficial to all-
I know growing up I was put in a very bad position with the parents divorce and it was 4 adult children driving all us kids NUTS! We did what we needed to do or say just to keep peace and today I'm recovering from living that life. IMHO I do not wish that on any child-The more they understand from counseling, meetings etc... the easier their life will be and yours! It will teach to throw the consequences of your x's behavior back on to him as you or your son should not pay for it.
Keep us posted and remember you and your son are what is important!