i think my husband is rude

Get rid of that husband, it's never too late!

Not enough info as is

First time this happens?

Were hellos exchanged between when she arrived?

What was your husband doing during those two hours?

Were there more guests or tasks to take care of?

So he doesn't even help with cooking the Christmas dinner either and leaves you to it?

My partner cooks most of the dinner Christmas Day, and I help (which is reverse to what happens day to day). He greeted Mum with a hug and a kiss, made her a cuppa, and made sure she was comfortably seated, and even chatted to her inbetween the cooking. This is normal behaviour surely, with any visitor.?

So yes, he is rude!

I went to my daughters for Christmas, when I arrived I went to the room my son in law was in and said hello and thanked him for inviting me then I spent the next couple of hours with my daughter in the kitchen, I did not expect him to come and speak to us.

At 92 she's a bit old for a high chair.

When my mum was with us she was provided with a suitable chair to sit in wherever the family was gathering. If there was only one chair she could use it was moved when needed. She spent one Christmas with a relative who seated her with 2 other older ladies and was deeply offended because she felt left out. She made sure we all knew about it. I wonder how your mother felt?

He doesn't sound very socially competent or caring but perhaps he just doesn't like your mum? seems a bit weird as presumably you've been married for a long time..

If mum was sitting in the kitchen with me while I prepared the lunch I would expect my OH to greet her and makes sure she had anything she needed, chat for a few mins then go about what he was doing.
I would not want him cluttering up the kitchen.

I would have dragged him into the kitchen to greet his MIL and pour her a welcome drink! Rude defintely.

Why not ask him these questions I don’t see at all how anyone here could possibly read your husbands mind to know why he didn’t go to speak to her in 2 hours ?? A mystery only he can answer and his answer will probably be ‘oh did you need me to I thought you were looking after her’

Could the higher chair not have moved to a more sociable spot?

It would take nothing to say Hello.. How was he with her at the dinning table? if they were fine leave it until they meet up again then tell him, don't ignore her, was he aware he left it 2 hrs?
Not defending him as I would have given my DH earache straight away and not left it.

May I be so bold as to ask how well your husband usually get on with your mum.
Did your mum pass any comment
Do you think she had a problem

Bit of a strange one! Presume she wasn’t alone in the kitchen? Presume your husband wasn’t alone wherever he was? Was he the only one who didn’t make the effort? What about after the meal, did she remain alone in the kitchen?

She may well have been Dinahmo but that doesn't excuse bad manners.

Perhaps you mother was enjoying herself sitting with you whilst you prepared the lunch?

No you are not wrong and in your position I'd have had words with him when your mum had left.

Talk to him before she comes over again, tell him he was rude on Christmas day and you don't want a repeat of his unacceptable behaviour.

Yes, he could and should have made the effort, but it was two days ago- let it go now. Don’t let it fester and cause a rift- unless your mother was upset, in which case he should try to make it up to her in some way. I guess she was busy watching what was going on in the kitchen then eating and enjoying the food and didn’t really notice.