@FatAndFurious7
YABU.
Both of you have to be comfortable and happy with who is invited ANYtime, let alone at Christmas.
Can you not just see these people a few days before, (like 22nd-23rd December,) and spend Christmas day and Boxing day with just him, and the kids?
I can never understand this obsession (some) people have, with having to be with everyone they are related to, on Christmas day! It would so much less stressful for EVERYONE, if they just met their extended family 2-3 days before Christmas, and maybe went out for a meal together. And then just stayed with their immediate family (partner and kids,) for Christmas day and Boxing day.
Seeing everyone you're related to (on Christmas day and often Boxing day too,) seems SO dated now. It harks back to the days where everyone in the extended family lived within a mile of one another, most women didn't work, and everyone socialised in the 3 or 4 pubs that were 5 to 10 minutes walk from where most of them lived.
Even then people would often just pop in for less than half an hour, and say 'hi,' drop a few presents off, and then tootle off to their own Christmas lunch. But now, there is this obsession with having to spend all Christmas day (and as I said, Boxing day too,) with extended family - who you often don't even like that much! 
I literally can't understand this obsession with having to see everyone you're both related to on Christmas day and Boxing day, and spend every waking bloody hour of those 2 days with them - even stopping over sometimes and even staying longer than the 2 days! There's 360 or so other days of the year that you can see each other.
And people needn't bother saying 'some people have other commitments throughout the year.' I don't believe for a second that Christmas is the only time people are available to meet up with their extended family.
And it doesn't help with passive aggressive and manipulative family members wanting to spend Christmas day and Boxing day with other extended family members, and making other family members feel like shit if they don't comply.
I know a few people who parents/grandparents/MIL/FIL would never speak to them again if they don't go and see them Christmas day and spend at least 4 hours with them. Or preferably, have them around, and wait on them hand and foot all day. (And Boxing day too!)