Sorry to read that things are still so contentious; that your children are stuck in a tug of war over which they have no control.
Cuz.. really. They are the children. You are the adults. You would not give them carte blanche to set their own curfews, decide to start driving, drinking, play roulette with loaded firearms, watch or buy porn.
Kids at this age aren't mature enough. Kids need both parents.
And each parent who's unable to see their child accuses the other parent of the same type of manipulation.
Something is extremely unbalanced when children below the age of driving have the control to eliminate a parent from their lives.. at least a non abusive, danger to their well being one.
With that said, it's probably to your advantage if your son continues to stay with you. After all, possession is 9/10th's of the law. And if this estrangement continues consider having something written in about siblings being able to have time together without worrying about being 'snatched' by the other parent.
In this contest of wills, no one wins. Don't respond or try to explain things to your divorcing spouse. Toss in the validation (I can understand why you feel that way) and let it go. This is a cheeseless tunnel coated with explosives.
Here's something from FIB's thread by Bworl:
"The important thing here FIB is that you WANT a close and regular relationship with your children. If you want it, you will find a way, through time and trial and error, to have as close a relationship as you can have given the situation.
I feel for everyone who lose that every day contact with their kids as a result of divorce or separation. The truth is that there is no perfect answer in these situations, which simply emphasizes again the sanctity of marriage and why it is important to do everything possible to keep a marriage healthy, viable, and lasting."
"Again I will say that your children will never doubt that you WANT to be in their lives each and every day. While that does not fill your empty times, it does mean that your children will never be without their father, whether present with them or right at the front of their heart."