Looooong story. Have posted about DS's dad before. DS is now 3 and a half.
His dad lived nearby for the first 2yrs of his life but moved to Cornwall (2-3hrs away by car) with his family in December. Contact has become very sporadic since and until this weekend he hadn't seen DS in 2 1/2 months (partly due to stress from the job resulting in a bit of time off).
He didn't want DS (unplanned) but I left the door open contact wise and things got better once he turned 2. He had him once a fortnight for almost a year until he moved.
DS went down there this last weekend for 2 nights and came back monday. I know kids often play up after contact and DS is no exception but he was awful. He'd been sick in the car so was shouted at a lot for that (so he was very upset when he came in). Then he was like a different child altogether in the morning. It wasn't just bad behaviour though, it seemed like he was quite unsettled but I had anticipated it.
Then he played up after nursery and was a nightmare to get to bed. I talked to him about the weekend as casually as I could to just make sure nothing had happened and as far as I can tell, besides being very shouty and his cousin being 'rough' it went ok. His dad has hit him before and DS has told me so I think he'd be able to tell me if anyone really hurt/upset him. After nursery yesterday I was pulled aside when I picked him up to be told that he'd been hitting lots of other kids, kicking, playing up, saying no to everything and all the rest. They told me because they thought something must have happened at the weekend as he's normally the total opposite and 'has never ben so bad'. So that was embarassing to say the least 
I just feel really bad for DS and don't know what to do. He's much better this morning thankfully. But his dad moving away shook everything up and now contact is all over the place and will continue to be so. His dad comes up here for work so I was thinking of saying maybe just visit him here for the day/take him out sort of thing. If you do have him at yours make it more consistent and just for one night at a time as you never see him more than twice a month and it's too much in one go for him, at this age anyway. AIBU?
It was just so upsetting and difficult to deal with that afterwards and he seemed really upset/angry when he came back.
I don't think his dad will be that bothered himself as he didn't ask after him once in the 2 1/2 months he didn't see him 
I don't know 