I asked DH this morning about his 40 year old brother coming over for Christmas lunch - DH replied "Didn't I tell you he was going down to x for Christmas to spend with aunts and uncles?" (x is the city 2.5 hours away that BIL is traveling to).
Nope - he had not mentioned this at all and I was under the impression we were hosting BIL (as DH said we were). I have been stressed by it as one of our kids doesn't like change of routine. Took us a while to realise Christmas is a lot more enjoyable and relaxing when it's just our nuclear family for lunch as it means no meltdowns.
Background - MIL passed away this year, shortly after moving to the town where DH and I live. BIL moved to our town when MIL was given her terminal illness diagnosis. No other siblings live close by. BIL is single, no kids and has never made the effort towards DH and the kids. He is a bit of a loner - and DH didn't want his brother to be alone on Christmas day - which I was fine with, given the circumstances.
For the last 26 years - MIL was never interested in spending any part of Christmas day with us, but always spent it with BIL (except for 1 year), sometimes SIL, and always with some of her siblings. She did invite us one year - and DH was so excited, but then she uninvited us a couple of weeks before Christmas because SIL would be there with her one child and there would be no room for us. (There was plenty of room around the table and in the house.)
About 24 years ago, we popped in to visit MIL's brother's family on Christmas day as they had invited us to visit after lunch. MIL and a few of her siblings were there for lunch - MIL totally ignored DH, DD and I, and she left quite quickly after we arrived. It appeared she was very uncomfortable with us being there - DH's younger siblings were spending Christmas with their Dad, and MIL wouldn't see them for a couple of weeks.
We didn't know MIL was having lunch at her brother's house and she probably didn't know we were invited over - DH had tried to arrange a time to see her, but she said she was too busy. At the time we lived 2.5 hours away from both our families and drove over for the day, so tried to plan it so we caught up with lots of family.
MIL was a bit odd and she seemed to keep her kids at arms length from each other - so catch ups with DH and his siblings was rare. Quite the opposite to my family when my mum was alive. We only saw MIL a handful of times a year because she always had something else to do - someone to visit, so we felt like we were on the bottom of her priorities.
My issue is that DH doesn't communicate with me, and doesn't get that I am not a mind reader. He found out that his brother had other plans via messenger chat with his siblings - I am not in that chat group! If I hadn't brought it up this morning, I would have been stressed for the next couple of days.