AIBU child behaviour, Dad bad influence

[jjsmum84]

I have a 4 year old son, his father and I have no relationship due to domestic abuse on his part, he sees DS once a week (court ordered) he has had DS this weekend for 2 days due to us being away last week, after just 48 hours my DS has come home swearing and spitting, his behaviour is usually an issue when he comes back from his dads due to there being seemingly no rules there, but this time it's awful!
AIBU to be really bloody annoyed?

No YANBU.

Definitely reason to be annoyed, however...you can't control what happens at dad's, only what happens at yours. Don't show anger at lo because of his behaviour. Just gently remind him it's not acceptable behaviour. Say something like: At mum's we don't pull the cat's tail/ swear at the postman (or whatever behaviour is unacceptable). Please don't do that.