If I am reading this correctly, you are divorced.  You do not have to speak to him anymore.  He has no say.  Your kids are grown.  Tell him to get his own life and leave you alone.

There are also legal ways to handle it if he does not get the point.  Restraining orders etc.  I would use that as a last resort.

Move forward and leave his mess behind.  take care

I have the same problem.  I was married 12 years, although no kids.  He frequently texts, e-mails, shows up and calls.  I have told him many times I am not going to re-marry him or move to a new location with him for his job.  When you never wanted to be in a divorce situation and then you have to get a divorce, it hurts.  Add to it the constant contact from an unhealthy person and my emotions are all over the map.  I get angry, sad, nostalgic and also feel relief I am out.  I had to pretty much cut ties. I hope this works out for you.  Keep us posted.

My ex told his paralegal that he intended to continue seeing whoever he wanted and when he got tired of running around he would come back to me and help me on our farm. I might add he married someone else two years before I got my divorce. Ours was a 33 year marriage.
I tried the friendly route. I can do that . He continues to play games . So I am cutting my contact to the bare polite minimum.
If you are not dependent on any financial support from him you can cut the ties by just not answering the phone when he calls. Let the answering machine take the calls and don't call him back. Because I do my own work on a small farm I forward my house phone calls to my cell phone. Only close friends and relatives have that number. I give the house number to repairmen, and people who I deal with on a short term basis. If I don't know the number I don't answer the call. Keeps things a lot simpler. If you see him on the street; go the other way. Just totally ignore him. I did that with an ex son in law and he said it didn't do any good to call me because I wouldn't talk to him. So when my daughter left him he knew he would get no info out of me and I wasn't harrassed by phone calls.
Get the opinion of your sons first. They might have some better ideas. You shouldn't have to do that for long and he will finally get the idea and you can set boundaries for future contact with your ex.