I completely understand your position of having negative trust (below zero) in your X. I feel exactly the same way with my X right now.
Sometimes I sense on your thread there is a lot of vilification of your X. I'm not standing up for the guy. But I also think it's counter-productive to your goals to engage in this thinking or discussion because you are focused on him.
My situation was not the same as yours, but some of the same aspects were there. My W insisted on a lot of conditions when I had the children. I complied for awhile, because we were working with a counselor and I thought it might help us avoid court. After several months I realized that wasn't going to happen, and that my W was not going to let go of the reins. So when she started offering conditional increases of parenting time, I said no. I know she thinks I'm (insert any label you want here) for not accepting her offers, but I don't really care, because I wanted to be a father to my kids without her controlling every aspect.
But I'm not your X, and he may not be interested in being a father in the same way. He could just be doing this to get back at you. I don't really know.
I don't actually have any advice on what to do. You are obviously right to have protective instincts of your son. I hope for you that you can avoid an expensive (emotionally and financially) legal battle down the road, but you can only control your role. Your H may be a loose cannon. Keep that focus on you and how you can stay strong and centered. Your S is lucky to have you
