Trying to cope and understand!!

My husband of 30 years adopted our children at ages 3 and 9. Ex did not pay child support for two years and did not see them for two years at the time. He had cancelled their health insurance and life insurance, and was doing nothing. He even took money out of one of the kids bank accounts. All of his family encouraged this behavior. My dear hubby hugged and loved and raised these kids as his own, taking them on vacations, teaching them to do things that would be helpful for their whole lives. Now, at age 33, our son chooses to take his four children to visit with this family who has caused so many problems. This man has lived with many women, and been divorced again. I thought I had him out of my life. There is a whole long story behind this, but I'm sure others deal with this kind of thing. I tried so hard to deal with him when I was younger and had to, now I just want to live my life and be left alone. This guy seems to think it is funny when he can get around me or his other ex, and it is like he is trying to harass us both. There are enough problems with the sons kids already, and now I have to deal with hearing about someone from grandkids who didn't care enough to take care of his own kids, or even provide a home where he could visit with them. He is getting older and just wants someone to take care of his sorry butt even though he didn't care . Anyhow, I wonder how many others deal with this. I couldn't even smile two weeks ago, now I am coming back.