It's a MIL one - stop me before I say something I'll regret

She agreed to the holiday with her son, OP and their DD back in the summer. It's obvious that the dates of the nativity have just been released. She should stick with the prior arrangement with her son. She attended the other grandchild's nativity last year. They have one full day for this 3-day break and MIL will miss most of it due to prioritising her other grandchild.

Of course OP is annoyed with her. Most people would be.

Point taken but I still think MIL is trying to please everyone and keep the peace

How can people be this dense? Hmm, I wonder, how could a mother possibly be bothered by her child being treated much less favourable than their cousin?

Thinking about this more ( I'm definitely avoiding doing work!)
I think that the relationship between your DP and sister must also be off kilter, because she is okay with taking their parents away from their short break with him and his family.
Would talking to her about this help? Because she should not be okay with this happening but maybe she doesn't realize the situation?

I'd try and bite my tongue, OP. It's not going to solve anything, is it? The holiday fall out didn't resolve it, they just revert back to previous behaviour at the first opportunity. They'll justify their shitty behavior with all the crappy justifications that have been spouted here.

Go and have a lovely time, let them do the ridiculous trip, avoid the passive aggressive remarks suggested here and don't bother making any effort to involve them any more.

I'm usually one for calling people out, but one thing I've learnedis when to let it go - people who don't care or just make excuses for themselves won't change. They won't see the light no matter what you say and you just end up more upset by it all.

Just to add, is there any way you could ask your parents/family members in place of them. Tbh, that’s what I would tempted to do, although it’s sad for your fil, who sounds lovely.

She's basically got a better offer (to her) and wants to do that instead. I would be pissed off too. If the situation were changed, and it were you're DD's nativity play, she'd miss it, wouldn't she?

This update makes it even worse! If they sat down and booked the activities with you, they know full well what a big deal the trip is. You have been far too conciliatory in your text response to her.

I hope you don't treat people like this, blow them off for a better offer? One full day and mil fucks off for the best part of it? Haha no.

If it makes you feel any better...my in-laws not only don't give a shiny shit about their grandchildren they go to huge efforts for their nephew and nieces kids that are the same age as their grandchildren! Net result our kids don't give a fig about them, and despite living minutes away hardly bother with them except when we make them.

Where are your parents @Bounty9? Can they come down and visit Santa with you all?

Isn't that ine of the first rules of manners? You don't blow stuff off for a better offer.

It doesn’t sound like she double booked herself. It sounds like the nativity was just scheduled and she’s changed her plans. I agree it’s very rude. In your position I’d ask DH to be honest and explain why it’s hurtful. No need to start an argument, just be honest about your/ his feelings.

what happened on this family holiday? We might need some context in order to balance the YABUs and YANBUs!

I absolutely get where you’re coming from, OP, and think it is a rude and hurtful thing for your mother-in-law to do. Ultimately, she is choosing her grandson over your DD, and I think you have every right to be upset and cross about that. It sounds like you’ve done a great job in building bridges and working around/ignoring the favouritism but I think I would have to say something to her about this, and hopefully your DH will address it with her tomorrow. Hope you have a really lovely time away, and are able to enjoy it, despite your mil’s actions.

What’s SIL and her husband like in all of this? Is MIL being driven by them?

Your use of the phrase 'quality time' is making me wonder if you are the unreasonable one.

Nope. It just encourages MIL to blow off OP when ever she likes.

A firm "oh dear, you are missing all the fun we planned, lucky we can get a refund" and that is it.

Why rearrange stuff for someone who would blow them off like this?

Yeah this. Child is 3. There'll be many other opportunities but possibly no other Santa visits where granny is invited.

I would be cross too.
Why is a nativity play so important?
It's just a bunch of children dressed in cut down sheets with tea cloths or tinsel halos on their heads doing something they have no clue about, mindlessly following frantic instructions from off stage.

Why would it end the relationship with her daughter?

they arrive on wednesday 11am? and leave on friday. so i imagine during those times.

I think MIL is trying to do everything and getting a bad rap rather than acting maliciously. I think arguing that DGD should be put "first" isn't fair! they're both young and doing christmas related things of course she wants to do both.

Taking it a personal slight against her grandchild is a bit unfair, if we can't give family the benefit of the doubt rather than assuming bad faith in their actions on first thought, whats the point?

Ditto here. My mum clearly favourited my DBs second son. All the kids (including his brothers and sisters) knew this and they would just roll their eyes - it didn't cause any life long rifts between any of us. So it's not necessarily going to cause any of the kids to feel 'second best'.

Saying that will END the relationship and likely make things worse and painfully awkward.

Can't you do Santa and lunch the following day? Center Parcs breaks are 3 or 4 nights so there must be a bit of wiggle room, even if it's the day you are travelling back.
Why 6 hours though? 4 max unless they are going to do something else with SIL. Even then you'll have two evenings with them and most of the leaving day, I'm assuming there's no need to hurry back on the final day.