I am so upset, FIL has refused to go with our xmas plans this year and now I don't know what to do.

Above Sounds like a good idea. I doubt there is much you can do to make a cantankerous person cheerful. Then enjoy cankantering too much.

and in reply to
"I am fed up to the back teeth trying to constantly appease cankankerous old men."

Although not wanting to sound too facile.

Just stop trying to constantly appease cankankerous old men.

You literally can't appease them. Why is it your job in particular (although it may feel like it) to devote all your energy to doing this? You are not the only member of the family. Spread the load.

Life changes, people pass on and so long established patterns will necessarily have to change. That is not your fault.
Its not that you are ignoring a person, but if they don't want to do something, that's down to them. They could come for Xmas eve for eg. Have a special Xmas breakfast and then be driven home to cantanker. Or change their mind and stay.

But you can't keep taken on a huge burden of guilt about this, when you know you are doing your best. Its up to others to accept or decline.

At some point in your life, when two partners have four parents between them, things start to change.
You are lucky you have had so many together celebrations, with your hard work and organisation enabling them. I mean that as a compliment - you sound like a fantastic host!
When things start to change, when a parent needs care or passes away, making plans doesn’t fall so easily.
I am going to go left-field here and say, let your DH spend the day with his dad. He may want to be in the family home, and feel close to his wife’s memory there.
We place so much pressure on this day. Now I’m without both of my parents, I realise how much I cherish my memories with them.
Your DH can turn up when it’s party time. You can have a lovely family Boxing Day in your own home.
I don’t think this seems about a cantankerous, nasty FIL who is being stubborn. It’s probably just too much for him.
Your family on both sides sounds wonderful. Cherish it, celebrate it, and if your plans for now and the next few years get a bit messier, go with it.

"we can not leave him to spend Christmas day alone"

Yes, you can
You don't want to, and you have offered him an invite so he's not alone, but he has turned it down
That's the end of the matter

This exactly!!!

You've got your plans. You've invited him. The rest is up to him.

Dm threw a spanner in a couple of years ago. We had her come to us all during the covid Christmasses and frankly, were looking forward to a break her included I suspect. She was invited to one of my siblings and at the last minute pulling out as she didn't want to go to my siblings inlaws for the dinner. Anyway, she came to us as there was pressure put on both her and us that she couldn't possibly want to be alone at Christmas.

She didn't want to be here and it showed. She genuinely would have been far happier at home. So the following year, I respected her wishes and video called her instead. She was much happier.

It's not easy balancing trying to keep everyone happy while still having your own Xmas to enjoy. I think really you need to have a bit of flexibility when dealing with elderly parents. Do you know he definitely wants company and hadn't just said no as he would prefer to be alone? There are ways around it when you live close by - dh can pop in I'm sure your day won't be ruined by spending an hour or 2 apart.
Also your plans are based on your mum being well enough she may be tired and want everyone to go earlier. Last year my df had a good spell of health until a week before Xmas when he was admitted to hospital and all xmas day plans were changed it's just the nature of elderly parents health sadly

I think your intentions are really good ones but he said no and that's ok too.

I have spent a lot of christmases at home with my two children, just the three of us and I loath it when people start trying to tell us what we should be doing at Christmas. Being home for Christmas is so nice, I hope your FIL has a nice day planned with whateverer food he wants.

I think you have to take him at his word tbh.

If it was my dad though I'd probably cook & have lunch with him.

Maybe as he has got older, your FIL may find it all a bit much for him, and prefer something quieter.
I mention this as I have been at a Xmas gathering where the elderly person clearly could not manage the continual 'small talk' etc., for such a long time.
I would ask if he prefers to be on his own.
Maybe ask him what he would prefer to do.

You're overthinking things.

Your plan sounds absolutely necessary for your mum's sake. YANBU on that score.

But your FIL is not being unreasonable either. He's used to a quiet Christmas lunch, he's an old, grieving widower who doesn't want to spend Christmas day with someone else's (comparatively large) family, and that's his prerogative.

Is it really such a terrible thing if your DH goes to his dad's for part of Christmas day? So many couples spend Christmas day apart because one of them is working. My dad used to work away on oil rigs, so we only saw him every other Christmas. It was fine! You'll still have Christmas morning and evening with your DH. Don't stress about it.

Why would you think that ? It doesn’t appear he wants to be alone, he just doesn’t want to go anywhere else but OPs home.

Remember that he is a grown adult, if he doesn’t want to be on his own he has a perfectly valid alternative that he is choosing to decline.
You are not in charge of organising the day for him - you are including him in your plans, but if he doesn’t want to be included that is his choice.

Sounds like a really good plan.

The only thing I’d do is to propose to him that arrangement rather than telling him iyswim. That way he is feeling in charge.
I’d also make sure to say it’s THIS YEAR organisation. Because, from what you say, he might well expect it to happen every year (you bringing lunch etc…) and you might not want it to happen every year iyswim

I empathise with you. I pandered to a close relative for over 20 years & Xmas was challenging due to one cantankerous person.
In hindsight I should have been more assertive from the beginning.
Though difficult, I would stand your ground & call his bluff. Good luck.

@Dreamsfallapartattheseams I get what you are saying about not wanting to leave him on his own on Christmas Day, but I really don't think you should mention this revised plan to him - at the moment. It's a good back up plan, however, if he won't come this year, this is likely to be your Christmas every year for the foreseeable.

So if it was me, I would simply tell him again, only that he would be very welcome to come to your Mum's. But don't offer him the back up plan at that point! Wait until much nearer the Day (like Christmas eve or even Christmas morning) and see if he changes his mind. Offer the backup plan to him only at that very late stage if you need to?

As it gets closer he may very well reconsider, whether or not he really does want to be on his own. If you offer him alternatives now, which might appeal to him, then you are going to find it is expected every year?

He has been invited and has said no. It is HIS choice if he spends time on his own on Christmas Day. Lots of people spend the Day on their own, for various reasons and I know several, personally, who are genuinely quite content doing their own thing!

.

Sounds ideal for everyone. Is DH able to see FIL on boxing day or similar?

I think you've made the right decision. As everyone else has said, it's not a case of you leaving him, it's a case of you offering him and him refusing. Which he is entitled to do.

If your sister or friend or colleague or someone was alone, you offered them an invite and they politely refused you wouldn't insist on enforcing yourself on them. You'd accept as a functional adult they had the right to choose what they preferred. Just because FIL is older doesn't mean he doesn't have the same right.

Keep the invite open in case he changes his mind but otherwise I think popping a dinner down to him is enough. I wouldn't even be that focussed on going to see him for hours in the evening, you'll probably be knackered from sorting dinner, helping with your mum etc. If you feel like it pop round for an hour, if not go round for longer on boxing day and take him for a walk or to the pub or something if he wants to get out of the house.

Christmas is just a day at the end if it - you can't 'fix' it for him, he will be missing MIL whether he's alone or surrounded by your family, in fact option B might even make him feel worse as he will be comparing himself with everyone else having partners, or reminding him of years gone by when you were all together having fun. At least being alone in the house is like a 'normal' day so might be less upsetting. It's entirely up to him to make that call.

My df was like that too, he would have hated being with anybody but very close family. Even then, he would get tired, and not stay too long. Some people's social metres get full quicker than others, and that is fine. My dm on the other hand I cannot get to leave. She hates her own company. I get tired and I'm ready for people to go after a couple of hours, obviously more allowance on Christmas day. Dm stayed from 12pm-9pm last year, and oh god I was ready for her to go!

Op, I would let fil know if he is happier with that, that it is fine, but he is more than welcome to come for tea later if he fancies doing that instead. Maybe your dh could pop in to see fil in the morning with a gift.

Plate up his lunch and drop it off at his house later. If he’s not up for it let him be. No reason to spoil everyone’s plans just drop in and see him later. He’s allowed to have preferences you do not have to allow his preferences to interfere with everyone else’s plans

I feel for you OP, Christmas can be a stressful time trying to juggle & please everyone, more so with elderly parents who like their routine.
Sounds like you’ve a good backup plan.
Hope it all works out for you so you can relax & enjoy Christmas 💐

You’ve invited him and he’s said no. I would go ahead with your plans - maybe popping in to see him in the morning and leave him to it!

I think your original plan was / is lovely and suited EVERYONE except FiL. It seems foolish to change those plans just because one person doesn’t want to join in. I think it makes sense to stick to your plans, but factor in a visit to FiL as part of the day. Which is, I think, what you’re now saying you’ll do.

This

You hadn't made it clear the evening buffet at yours was not on offer this year. Tbh it sounds as though you're pissed off you may need to change your evening plans as FIL doesn't want Christmas dinner with everyone else.

Look, it's one day. Take him a dinner and your DH can visit him on Boxing Day.

Of course you can leave him alone, you offered for him to come to your parents house and he said no. Why would you change your plans?