DS's bio father has never observed xmas, nor do his parents. He was raised hardline atheist and they didn't even acknowledge it in a secular way once he (only child), was out of childhood.
DS is 10. Every year I have invited his father to come over to ours for xmas (he lives 5 mins away). Every year he has refused. So every year DS has had xmas with me, DH, DD and DS2 (4 and 3), and our extended families.
Then his bio father would have him from boxing day and take him to see his parents for a few days (they live four hours away).
This year his bio father has decided he wants DS for xmas, and that "in our situation" people alternate xmasses. So he is proposing that next year he will take DS on xmas eve and take him to visit his parents for xmas eve, xmas day and boxing day. So DS will miss out on xmas and seeing his relatives and everything we've done every year since he was born, and be stuck inside with his elderly DGPs, no tree, no santa, no presents and no siblings.
AIBU to think that's just really crappy? I have offered for DS's bio father to have him for longer, to have him before xmas, all sorts - including driving the 4 hours each way to get DS and bring him back so he can spend a bit of xmas with us.
DH has to go back to work on the 27th every year, which DS's biodad knows, so things get back to normal with a bump around then anyway.
Gahhhh :(