To be hurt that MIL won’t attend our wedding?

I still think you should try and talk to your MIL and/or your SIL.
It will be a difficult day in many ways in terms of your FIL no longer being around but could you find a way to include him in the service? Perhaps a treasured photograph strategically placed? My friend whose father is no longer alive had helium balloons with her Dad's photograph around the reception. I know this sounds a bit tacky but trust me it wasn't and it was a really lovely tribute.
When a loved one is lost all future family events become happy/sad if you could show your MIL you understand this it might help.
Good luck with resolving and I really hope you do.

This is such odd behaviour OP, I can't get my head around it. I'd fly across the world to attend my DCs wedding. What have your parents said about it? It's going to put a real dampener on the day.

It’s a very small civil wedding with only my parents, siblings and DPs mum and siblings invited.
Is there a chance she doesn't think it's a "proper" wedding and not worth her time? Stranger opinions have been known. Did she want a bigger one so she can incite more friends and SIL is similarly not taking leave because she doesn't think it's a big enough deal to be worth it?

People do get very fixed ideas about what's appropriate at weddings and lose their heads if they don't see the wedding type they expect

From your posts OP, the family have had a few months notice of the wedding. So reading between the lines you booked a wedding knowing BIL wouldn’t be able to attend as his partner is about to give birth, not invited SIL partner, and booked a wedding on a weekday (are kids needing school runs an issue etc.). Could this be the case? If so, it’s obviously your wedding and completely up to you how you want to celebrate and invite who you wish, but they are also entitled to feel upset not to be considered and decline.

personally if this was the case I would be miffed my DP didn’t get an invite, but would still attend because it’s not worth an argument. But family’s can be strange with these things.

i would also take your future DH lead. Unless he wishes to bring it up, leave it be, it will either blow over or the family will show you who they are.

enjoy your day and do your best to put them to the back of your mind.

I think there is a back story OP- just not one you’re aware of.

MIL sounds controlling and SIL is a chip off the old block. ( and dare I say both have narcissistic traits?)

the fact that your DP doesn’t ever raise these issues, suggests he’s learned to do it as a coping mechanism and is actually regularly on the receiving end of this kind of horrible behaviour.

unless your SiL is going on a BIG holiday/ maternity leave and needs every scrap of leave, then I can’t see her decision being justified. I’d take a days leave for a friend’s wedding.

So did you invited Sil/bil partners? Could that be the issue?

I think SIL is key here. My guess is SIL doesn’t like you and may have bitched to MIL who has then agreed and nodded along, regardless of her feelings towards you (she may dislike you too and is happy to pretend otherwise when around you). MIL may not be very confident enough to go to family stuff without SIL if they are close and she the golden child, or will not want to be seen to cross SIL given she knows her opinion about you, and has possibly agreed with.

Either way they have shown true colours I would back way off in future. Give the same excuse if SIL gets married.

Perhaps not try to persuade them to come, but point out to them that this can't be undone once the wedding is over. This is their son/brother and there's no going back in time to witness one of the most significant events in your lives.

How reasonable is SIL? Could
You say this to her and tell her how hurt your DP is in the hope she'd change her mind?

did either of your DP's siblings get married? did she attend their weddings?
do you think she would?
you don't have to scorch any earth, but it would be good to both talk to his mother and explain in simple words how hurtful her attitude has been, and that this will mean a change in how you treat her in future - she can't expect you to show her the same care and respect you've shown her up till now, or be as available to help her, she shouldn't expect the same level of gifts/ cards/ visits from you both, and your wedding photos/ children will not be available for her to show off to her friends!

It's just so odd not to go to close families weddings unless a massive fallout, everyone will be wondering where they are

‘No we’re not going to do copies of the photo album, you’re welcome to come and look at it here of course. Surely your friends would find it very strange that you didn’t come to your own son’s wedding, would you really want to show them photos of us with just my family celebrating with us and not his own?’

100% agree with this. Be led by your DP. It’s his family. They may be rubbish communicators but you can be open. Preferably DP should lead this, but if not you should let all of them know how sad it makes you to not have them there. His dad can’t be there but they can be.

Try to find a solution to them joining your celebration, e.g. if wedding on a Fri and SIL won’t take leave, could she meet you on the Sat for a family post-wedding lunch to celebrate? Or could you plan a family celebration later when BIL’s baby has arrived? Try to have empathy for your MIL. Her DC’s wedding must trigger bereavement, make her miss FIL and feel lonely/unconfident.

Aim to remain on good terms. Once family rifts start, they’re v hard to rectify. And if you have kids, she’s their GM. But focus on your DP and having a great time with all the people who want to be there to celebrate with you. They’re the people who you can rely on. And I wouldn’t trust or rely on MIL or SIL, or try to get too close to them, given they’ve been like this about your special day.

This

This totally!

Absolutely this.

Sorry I’m another one who thinks there is more to this story. Having been the family member to an unreasonable in-law who decided to disinvite me and DH to a wedding, then lied to the whole family to say we decided not to come because our DC was poorly - you need to look at your own behaviour too.

did you knowingly book a wedding knowing SIL will be heavily pregnant and not be able to attend? Not invite parters etc?

So from the outset they were clear that they weren't going to be attending.

I think with the utmost respect to you here @CheeseSnacker, this is more of a 'you' problem to get past and not a 'them' problem to fix. If your soon to be DH is disappointed but has managed to accept that this is what they will do. You have to follow his lead here.

They know there is an invitation open to them to attend so if they show up - great. Otherwise, just crack on with your wedding and have fun without them!
That is my honest advice here.

Is there a possibility that SIL/BIL are not coming in support of MIL? That certainly happened my situ.

The whole situation is quite bizarre in that the refusal is from a MIL who you seem to get on well with, on the face of it. As DH will not confront the situation, you need to commit to not caring. Make the decision to enjoy your day and your life and view it as MIL’s loss. I had a poor relationship with my PILs - there was no pretence of friendliness - and once I understood they wouldn’t change their characters or views, I stopped caring and was so much happier.

They’re the ones causing unnecessary bad feeling! How very strange to not want to go to your son/brothers wedding! Just wait till you have kids, they’ll be even worse. I’d be taking a wide berth

I actually think DPs sister's reason is worse.

You know this thread would have made a lot more sense and cut out some confused guesses if you’d just given this info in your OP? 😆