To want to have all the siblings and grandkids together at Christmas

She mentions hosting herself but says that her parents only want Christmas in their own house.

I personally find it really odd that they don't want to be all together - my parents just love it when everyone is able to get together. I wonder why they would not be willing to come to you, seems unusual. I don't think you are unreasonable.

Why not invite everyone to yours for Boxing Day?

I think it sounds like this is what the parents want anyway, they don’t want everyone at their house and they don’t want to go anywhere - they’re asking (around the houses) to have a quiet Christmas on their own.

I mean she and her sister might have to be firm about not going to the parents and having Christmas at her house instead - to which the parents are invited to but they’d have to leave their house. It sounds like the only way they’ll have a big family Xmas. Her parents might even like not having to cook etc if they tried it. But it might mean the parents have Christmas alone at first too.

I agree, I think the OPs parents will be delighted to be left to have a quiet Christmas Day, they don’t want a stressful noisy houseful of guests and that’s totally up to them.

You might have to be firm and not go to your parents if they don’t agree.

The parents don’t agree, and they appear to be fine with, indeed encouraging, the OP and her family not going to their house every Christmas, so not sure what “firmness” here is trying to solve.

I get what you’re saying. I think you’re going to have to speak to your sister and parents and say that you are sad that your children won’t see each other on the alternate years and you’ll never get to spend time with your sister.. I’d say that you think it better if YOU host Xmas on those years and you will pick up your parents if need be. You might have to be firm and not go to your parents if they don’t agree.

You've got rose tinted glasses on.

We always have a big Christmas and it's a fucking nightmare.

My nan loves it. All her children and grandchildren, meanwhile the house is too hot there's no where to sit, family politics and people talking out of their arseholes like they're the fountain of knowledge, kids complaining, presents getting mixed up because there's nowhere to put them out of the way, so much noise, tears from at least one person and not necessarily a child, performative gratitude, something getting broken, either feeling like you're not helping and you're being judged or helping and being in the way, someone is always in the bathroom every goddamn time you're busting, kids/men piss on the seat or around the toilet and/or don't flush, guests outstanding their welcome, feeling like you want to pull your hair out and stand atop a large hill with a megaphone and scream into it, and being too knackered to enjoy the day.

I'm sure this isn't a unique experience in our house. Perhaps your parents are just as sick at the thought as I am?

This is a good point I think

No I think the OP could invite their sibling plus family on the year they’re not with their in laws if that’s really important.

It could be something totally daft like not enough matching crockery or wine glasses. Too much noise, kids squeeling and shrieking.

Maybe too late for this year but would all of you going out for Xmas lunch work?

I am an introvert but there is no way my whole family wouldn’t be welcome at Christmas (bar serious illness, disability etc). We used to sit on the end of armchairs at my own Gran’s tiny bungalow. It also sucks to feel that what you do is determined by people who feel their plans are more important than yours! YANBU to feel disappointed.

YANBU to "want" anything at all.

But YABU to think that other people should change the way they want to host, to suit you.
As so many others have said, many people find hosting that many people completely overwhelming. Not just older people. Lots of people would.

You have unreasonable expectations, particularly as you aren't even the one doing the hosting.

You can’t make them host you all if they don’t want to. You host a different party on a different day and invite everyone. I love all my family together , but people have lives and in-laws or cba with a sit down dinner for 14 on a trestle table. Your whole family party doesn’t need to be on Xmas day.

I agree with you OP. If I've understood your post correctly, the kids will never spend Christmas day with their cousins, which is a bit crap for them. Have you discussed having your parents to yours and arranging for them to be driven home afterwards?

I think the awnser is for you to host something on Christmas eve, boxing day or new years and invite all the people you want to that.

The reality is that you cannot and should not volunteer others (in this case, your parents) to host a Christmas they are not happy with.

Since they're hosting, they decide what suits them and extend the invitation (to your or your sibling). You then get to either accept or decline depending on what suits you.

The good news is that, living fairly close by, even if Christmas day doesn't work out, you can either host/visit them on Christmas Eve/Boxing Day, both of which are just as much fun and less pressure imo than Christmas Day.

Not everyone has enough space to comfortably seat 12 people for a big Christmas dinner, I wouldn’t enjoy having that many people in my house, it’d be claustrophobic.

The OP has said her parents don’t want to go to her, sounds like OP needs to take the hint to do her own thing and stop imposing on family who just want a quiet day.

That is, if I went along with it, the years I am allowed to spend Christmas with my parents would be determined, like a buying a house chain, by when my sibling’s SIL can go to her parents.

It doesn’t sound like it’s about when you’re ‘allowed’ to see your parents as much as when you’re actually invited, I think your family is trying to gently tell you to have your own Christmas with your DH and kids & let them do the same.

It may seem like an obv solution would be for my or my sibling to host. But my parents want to be in their own house at Christmas.

Do your parents want you to all descend on them for Christmas at all? It sounds like you’re really not taking the hint here that your parents don’t seem to enjoy these big busy Christmas ideas you have and would prefer a quiet day alone.

Is it just Christmas Day they want alone? Would they come to you Boxing Day?

"Why should my kids not see their GPs for Christmas based on someone else’s schedule?"

I don't really get this - your parents don't want you there every year, so your kids aren't seeing their GPs for Christmas every year anyway?

That isn't "the solution" though, is it, because OP's parents have been very clear that they don't want to spend Christmas away from their own home. People aren't chess pieces, you can't just move them around to suit yourself.

OMG only on MN is 12 immediate family members on Christmas Day insanely crowded and overwhelming. YANBU OP having your family together on Christmas is perfectly normal.

Once elderly parents can’t cope with hosting their own children and grandchildren then it’s time for hosting responsibilities to move to the next generation.

The solution surely is one year you are all together at either yours or your sibling’s house. Then the next year your sibling goes to their ILs and either you host your parents or they host you.

the OP said, they don’t like all the family there at the same time. So really she doesn’t have a leg to stand on, as the hosts don’t want to do it in the first place, regardless of siblings-in-law plans!

I can understand your frustration, but I can’t really see what you can do if others don’t want it. Maybe host a big family get together in a not Christmas Day? Birthday celebrations instead? I think sometimes there’s too much pressure on Christmas Day.