Who would you like to be with you on Christmas day? I know that we are supposed to think of others at such times, but we all have had a tough year and can be excused doing what we want for a change.
DV6 If you want to have your sister, then have your sister. If he uses that as his excuse to stay away, then that's what it is, an excuse. Don't try to please everyone and juggle everyone else's needs.
Presume that he isn't coming and plan what you want to do. The only important thing is that you and the kids have a good day. And that will happen irrespective of where he is and where you are.
Tell him what you have decided and let him make his choices.
