Xenoplastic: involving distantly related individuals.
Am I still related to my in-laws? I haven't had any contact with any of them since the divorce, but does that mean we aren't related anymore? Is xenoplastic not a word that describes us?

Ex's Uncle B and Aunt J were really nice to me the whole time Ex and I were dating and then married. They had us over for dinner a lot, and we went to their church a few times. I miss them. His sister told me I was the sister she never had. Ex's mom liked me more than she liked Ex. But I accept that, in divorcing Ex, I removed myself from his circle of relatives.

Did Ex accept that as well? No. He did not. Ex continued to talk to my brother-in-law and they are still facebook friends, even though my brother-in-law knows it bothers me. Ex even went to their house once after the divorce! That nearly killed me when I found out he had been there. I felt betrayed. It still hurts. He didn't think of xenoplastic as relating to him. Ex was exempt from normal societal rules.
As I'm writing this, I can't believe my sister invited Ex into her home. I saw a picture of him with his arms around MY nephews. The pain is sharper than it should be, this long after the fact. I am unbelievably angry right now.