Dec 25 is also my son's birthday. We have spent the holidays with DH's family since 20 years before DS was born and that is not going to change. We give him the option of getting his presents from us before we leave or when we get back (we usually go for 5 days). He always picks before we go (he will be 6). He gets plenty of gifts from the rest of the relatives on his birthday and we don't worry about it.