Ex hasn't seen the kids since November 2020. He has not contacted kids. He has barely been in touch and for a long time insisted that he would have nothing to do with them until they were over 18. He has missed two birthdays. Suddenly he has agreed to come to another birthday but only when all the other relatives are present for a party. I'm thinking it will fuck with their heads once again. I would rather ongoing contact rather than him turning up like Santa in a birthday and then disappearing.