Okay y'all I'm going to try to keep this short. Going on 4 years of recovery but have really battled this for about 26 years. Starting to spend time with my adult children. I have never had a come to Jesus honest conversation with either of my children. My son has always avoided it. It just came to my understanding that he is believing a lot of lies that his father has told him that has made a tremendous impact on our relationship. The magnitude of what he believes is incredibly damaging. I run a very honest program and if I had said that something had happened that caused this I would take ownership. A friend of mine that knows everybody involved told me a long time ago that from 8 years old and up my son has been told lies I didn't want to believe it and now it seems it may be true. I don't want him to have to face things like this but I can't bear to have him believing just catastrophic lies about me. I just don't know what to do.
Hearing this breaks my heart for you, carrying that kind of pain while holding down 4 years of solid recovery takes so much resilience. Trust me I get it. The hardest truth in recovery is that we can’t force someone to see the truth until they’re ready, but your consistent presence and honesty speak louder over time than any lie ever could. Keep showing up, love him where he’s at, and let your changed life be the proof he eventually leans on
Honesty is best policy. How old is your son? Sometimes actions speak the loudest
Ugh Im sorry! Ive had similar situations :-/ Not fun ugh.
Although it pained me so that friends or family were listening and some believing lies about me, the "real" ones took the hearsay with a grain of salt. And some of those that werent as wise or were immature and young eventually knew they themselves would need to make any decision on their own. I believe your son will too, no matter what poison his pops might be putting in his ear! You just keep on doing good and keeping honest and it has to work out 
My ex dropped my kids off for a normal weekend visit. Kids were 8 yrs old, boy, and 11 yr old girl at the time. Then my ex never came back. I was barely a year sober at the time and trying to get my head above water. My ex resurfaced a few months later and tried to tell the kids it was all my fault. Told them both a bunch of lies about me...to justify her awful behavior. I'm sorry you are going through this. In my experience, the kids are smart enough to see the truth in any situation. 