DP and I have been together for 10 odd years but so far have never spent Christmas together. We met at uni and back then it made sense to go back to our parents for the holidays, as it also did for the few years after when we lived in small city flats.
However, we got our own house a few years ago, and since then, DP has made vague noises about hosting it here. The house is close to his parents so it would be neat way for everyone to be in one place for the period.
Last year when the house was more ready for hosting I put that to my parents. My DF seemed perplexed by the idea and eventually said: "I don't really see why the usual arrangement would change unless/until you and DP have a child, in which case you might want to do your own thing. It's quite normal for children to see their parents for Christmas". He said he had no problem with DP coming with me.
I was a bit shocked at that. I really enjoy Christmas with them but there is nothing really that couldn't be replicated over here. It's always quite a low-key affair and the main thing is being together. After mulling it over with DP and no signs of my DF budging I agreed just I would go as usual, but I said particularly with DP and I getting married this year it would be nice to look at them coming here in the future. DF seemed to accept that and later on in my stay started asking (in a nice way) about what we'd like to do when we host at ours, what traditions we might start etc.
Fast forward to this year! We haven't been able to see my parents much because of the virus. DP and I agreed together we would be happy to isolate for two weeks and then host my parents here. This year their house is off the cards as our car is out of action and I don't think I can sit on a train for a couple of hours and maybe bring them the virus. DP said he wouldn't see his parents while mine were here - at most he'd maybe sit in their garden at a distance - which I thought was very good of him.
We put it to my parents this week that we should probably start thinking about Christmas and we were thinking of the above plan. DM told me privately that she was on board and would just really like to spend time together. DF told me we had sprung the idea of Christmas on them too early without them having had a chance to think! (We've already had our tree up for a week - not sure about you all 
). I said I'd give them some time but my DM told me she thinks it's unlikely he'll agree as she thinks he wants to feel control over the period. In another conversation later this week he said maybe they'd come for one day but not stay the night.
AIBU to not really understand his position and think it's a real shame, particularly when we've seen each other so little this year? He's happily stayed over at ours at other times in the past, so I don't think it's an overnight thing. I also have a sibling who's been able to do their own thing for a fair few years now without comment from him!