SIL furious about Mother’s Day, were we wrong?

Background:

I have no children so always see my parent’s on the actual Mother’s Day / Father’s Day to celebrate.

I have several siblings who are parents themselves however and quite rightly the actual day is about celebrating them / their partners so they organise something with my parents for another day.

This has been our usual routine for years.

The situation:

My siblings took my parents out for lunch to celebrate Mother’s Day last Saturday; this included my DB. I didn’t attend as I already had plans with my parents for yesterday.

DB was supposed to be taking SIL and their 2 children out to celebrate Mother’s Day yesterday however late Saturday afternoon, SIL’s mother called to say she was back early from holiday (after having an argument with her partner) so was available to celebrate Mother’s Day after all and invited all her children and grandchildren to her house but NOT their partners as she wanted to just spend time with her children and grandchildren only. SIL decided to take her mum up on her offer and cancelled with DB saying her mum was probably upset about the falling out with her partner, they could celebrate another time etc. Considering it was Mother’s Day, DB accepted it with good grace as at the end of that day it was SIL’s day so he wanted her to do what she wanted.

My plan was to cook for my parents at home however DB called to explain the situation and asked if we wanted to go out to eat as he had a reservation for 4 people going begging (it was too late to cancel and he would have lost his £200 deposit) so my parents and I agreed and went to the restaurant he originally planned to take SIL and the kids too. Now just to be clear, I paid for everyone in full (gave DB back his deposit) as it was supposed to be my treat anyway.

SIL is now furious with all four of us and our “disgusting behaviour” and after several tongue lashings is not speaking to any of us.

The way I see it, SIL cancelled in favour of her mother and so DB was at a loose end (we didn’t hijack him away from her), he was going to lose £200 for the reservation but now hasn’t (in fact he got a free meal out of it) and SIL is still free to go to the restaurant another time like she suggested herself. It’s also not like DB spent the day doing anything nefarious either, he literally spent Mother’s Day with his mother only because SIL wasn’t available. I honestly don’t see how SIL lost out by us going instead.

So were we wrong?

Oh and just to be clear, there is nothing particularly meaningful or special about the restaurant other than that it does good food; we’ve all been there several times both together and separately. In fact, we’ve been going there as a family long before SIL was even in the picture so the particular restaurant is not the issue.

To answer a few questions:

We’re in London and £50 a head deposit is quite normal for “occasion days”, the restaurant doesn’t make any distinction between adults and children unfortunately which is why it was £200 in total.

I hardly think I’m a doormat, I paid because it was my plan / my day to treat my parents as per my OP (my DB already took my parents out and paid the previous weekend for Mother’s Day so not sure why you think he should pay twice) and I had no problem paying for my DB just like he’s had no problem paying for me on other occasions. Also, I was able to cancel my online shop which was arriving on Sunday morning (I had planned a 4 course meal with nice meats, cheeseboard and alcohol) so I wasn’t out “double” money if that makes sense. There was also no pressure from my DB to take him up on the reservation, I was actually grateful at being saved the work as I’m not doing too well at the minute so I was for it. If I decided I wanted to stay home and cook he would have just joined us with no issue.

Yes SIL is a difficult character but we’ve never really been on the receiving end in such a way before (she’s usually placated) so it’s come as a shock.

To those asking, I don’t know what SIL’s problem is which is why I thought I’d ask here, I don’t think we’ve done anything wrong but when you’re on the receiving end of such forceful anger it makes you question yourself which is why I thought I’d ask here in case there was something glaringly obvious we’d all missed. She was literally shouting down the phone so it wasn’t a two way conversation where I could get any sort of coherent answers out of her. Her complaints were all very vague “I can’t believe you would do that”, “how dare you treat me and the children like this” etc. She also does know I paid as she said “you paying doesn’t make your disgusting behaviour any better, in fact it makes it worse” which I’m completely baffled by, did she think my DB should pay?!

As for my DB, he has no clue what her problem is either (she’s told him that if he doesn’t know, she can’t help him) but he’s furious about the whole situation; as far as he’s concerned he invited us so my parents and I haven’t done anything wrong so any problem SIL has should be between them and she shouldn’t have dragged us (especially my parents) into it and she certainly shouldn’t have spoken to us in the way she has. To be honest, it’s opened up a whole can of worms between them about SIL’s mother and how controlling she is and SIL’s inability to say no to her.

From my understanding, SIL didn’t have a good Mother’s Day so maybe you’re right and that’s actually the problem; SIL’s mother is equally as difficult as SIL so maybe that’s another side to it.

😳 wit your update I can only assume FOMO from a lovely meal and the fact she had a shit day due to her own mother.

Perhaps your DB was supposed to either stop SIL going and/or also have a shit day and be miserable too? Plus be £200 out of pocket.

Why didn’t you split the bill with your brother? I can’t believe he took all the money from you. I would imagine brother accepted OP paying as he had been part of the previous weekends meal(and presumably contributed financially) to celebrate his Mother.
Does SIL resent her husband seeing his mother on Mothers Day, rather than spending the day with the Mother of his children? What, I'm trying to clumsily ask is, does SIL have a problem with her MIL rather than with you FreakingOutRightNow123.?

What does FOMO mean @RandomMess ? I can't work it out!!