Sorry this is long....
My ex (DS's dad) and his partner are splitting up. It's been going on since well before Christmas and they are currently still living together albeit now leading separate lives. DS is 7 and has understandably been quite emotional about this and really quite confused. School are aware of what is going on as he got upset in class - I asked for some help for DS & his dad (and me on how to handle the situation) from the school counsellor but when DS saw her and she asked if he wanted to talk he said no, she then asked if he had someone to talk to and he told her he had me. His dad never made contact. We have noticed a change in his behaviour when he comes home from his dad's - getting upset over the smallest of things, being mean to his sister and shouting/crying/angry - saying I am mean if I ask him to do the smallest of things.
I get on quite well with the (soon to be ex) partner and ended up chatting with her earlier this week. She mentioned some things that made me feel quite concerned. For example she got home to her belongings on the driveway on one of the days DS was there. She said DS's dad has sent her death threats, faked a suicide (but wouldn't go into detail), locked her in the bathroom and videoed her saying she was erratic and unstable. She said he gets DS upset and sends him to her crying asking her why she is leaving him. DS has told me that him and his dad have bought her gifts "but daddy said she can only have them if she stays".
My relationship with him when we were together was toxic (luckily I got out of it whilst pregnant with DS so he was never exposed to it) and although it never went this far, I can imagine him behaving like this. He very much likes to twist the truth to suit his own narrative and make himself out to be the victim. The soon to be ex told me that at Christmas, DS's dad had told her I wouldn't allow DS to spend the day with him and he would be alone when in fact we'd agreed (over text luckily) that DS would spend Christmas Eve with him and come to me Christmas morning because, his words, he would rather DS be around lots of family instead of it being a quiet one with just him and DS at home. There are many more examples of his worrying behaviour but I hope this gives enough of a glimpse of the situation without drip feeding.
Should I be concerned that DS is being exposed to this twice a week? I have no control over what he sees, hears or what he is told. Is his behaviour when he comes home typical 7 year old behaviour or could the situation at his dads be having a huge impact on his mental health and I should be doing something to protect him? How do I protect him without causing WW3 between his dad and me?
YABU - he is his dad and you shouldn't interfere.
YANBU - you have a right to be concerned and need to do something about it.