Mellow with time
After 16 years, the strong emotions have subsided.
His kids are 28 and 32 and have their own families and have moved away. His son talks to him and visits, and his daughter chooses no contact. She visits our town but doesn't call her father. I have no contact with them whatsoever.
My ex is dead, and his ex leaves us alone.
Our marriage is calm and happy. Our kids are in college and have their own lives.
Advice: it gets less complicated when everyone stops caring.
Stop trying to be friends with people who never wanted you. You will only make yourself sad and frustrated.