I have DC age 10, 5 and 16 months with exP. We separated when I was pregnant and he chooses not to see them at all. I'm not sure where he's living but he works in the town we live in and his job means we cannot attend community events as he's likely to be there which is obviously disruptive to my DC.
He has also been bringing his older children to the town on his days off (even though I'm pretty sure he isn't living here and his DC live an hour away) - my friend saw them at a park just 5 mins from my house where I take the DC almost daily. It's almost as if he's trying to stage a meeting, yet he has said he doesn't want to see them 
His job can be all over the country so I think the least he could do in this situation is to leave the area so as to remove the possibility of bumping into him. Especially with his DC; how he cannot comprehend how hurtful it would be to see him with his other DC knowing he doesn't see them is beyond me.
I really feel like asking him to move away if he isn't going to see the DC. My eldest is about to start secondary and the two youngest are settled here, I've just got a new job - we shouldn't have to and don't want to move. AIBU to ask the question?