After we divorced, ExH moved 200 miles away, got re-married and had another child. Our 2 DC live with me for the majority of the time but pre-Covid he had them every other weekend. He did the driving as it was his choice to move (his new wife’s family doesn’t live in their new town). During lockdown we’ve split the DC’s time equally, swapping over every 2 weeks and doing equal driving.
DS went back to school last week and is having weekly sessions at school. It’s completely changed his outlook and he’s back to the sunny kid he was before. Obviously this means he’s had to be with me so he can attend school.
Yesterday, exH kicked off via email because I was ‘manipulating’ him into spending less time with DS. Somehow, he’s decided that the school sessions are of no value and that DS should be with him. DP is handling it because any interaction with exH throws me into real distress (yes, I’m having counselling). But I’m so annoyed! I gave him advance warning as soon as the school started making noises about them going back, then gave him various options to suit him while getting DS to the sessions, including me driving backwards and forwards to collect/deliver DS before and after sessions when he was scheduled to be at exH’s. He chose the one where DS would spend the first weekend with him, then return here for the remaining 2 weeks while DD stayed with him.
He seems to live in his own fantasy world where even having actual facts and array of choices isn’t good enough and I’m an evil witch trying to keep him from the DC. Yet he chose to live 200 miles away and has steadily reduced contact with the DC from our initial arrangement. Not me 
The DC also come home and repeat crap he‘s said about me mistreating him or about how much he does to support me financially (none of which is true), while I make a point of never badmouthing him to or infront of the kids.
It’s just so frustrating and unfair and I wish he’d just do one.
/rant