Aibu - BIL's wedding

Don’t make it about the cost when it isn’t about the cost.

I’d be clear I’m happy to fly my family out to a wedding my family is invited to. But if we can’t all go then just those able to attend will fly as otherwise we will be wasting money on 3 flights.

Absolutely do not spend money you can’t afford on someone else’s wedding. Particularly a wedding where you and kids wouldn't be invited to 90% of it.
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Jesus Christ many people don't even spend 11k on their own wedding, never mind someone else's post wedding celebration.

Your BIL and SIL are being ridiculous - it's outrageous to expect people to travel 8 hours and either leave their children 8 hours away or have someone else travel a 16 hour round trip to babysit.

They are completely entitled to invite who they invite to their wedding. They're outrageously rude to think that their wishes mean you must comply. You're completely entitled to do what works for your family.

If they had any manners your children would be invited. It's a ridiculous distance to expect family to travel when half of you aren't invited to the whole thing.

You definitely aren't being unreasonable.
It seems they are making it really hard for you to attend this event as a family but are getting annoyed when you quite rightly don't want to spend a huge amount of money on an event your family cant attend.
If BIL wants to discuss the whole family attending - great. But if he thinks its OK to suggest your DM comes over at vast expense to essentially babysit - he's being silly.
He chose a child free second marriage ceremony abroad - fine. That choice has consequences, Your DH attends solo.

That's not an invite. That's not a wedding either, that's already happened. It's a party.

However, since it is completely outside your budget to pay for the shenanigans, if they offered to pay for your entire trip + babysitters etc. then I'd go.

Otherwise it's DH on his own or none of you go. Forget the flying monkeys, you are adults. DH must (unless entire gig is paid for you) be firm and go alone.

Your bil is being ridiculous. Your husband, his brother, just offered a compromise. The brother just wants his own way.
How dare they expect you to pay that amount of money for a wedding. Nothing to discuss, don't go. If you give I on this, the entitled brother in law will start wanting other things.

YANBU

Your DH going solo is the only option and definitely not unreasonable. In fact with most of these dilemmas the most frequent Mumsnet answer is always “well can’t just one of you go?”

If you all go (even if this was desirable financially) it sounds like your DH would be the only one attending anything significant anyway!! So to your point - why would you spend ££££ and hassle of small children to do, what exactly??

If they were that bothered about you personally being there with your DC then they wouldn’t have imposed their strict age criteria!!!

Of course YANBU.

I simply cannot get my head around people expecting guests to fork out thousands to attend a wedding.
I could never, ever imagine being so self absorbed and entitled that I'd expect anybody, not even close family, to fork out on airfares for a few hours at a shindig.

Your BiL and SiL are perfectly entitled to have the wedding they choose, in the place they choose.

Any invited guests are perfectly entitled to accept or decline the invitation and the bride and groom should accept that a distant venue, whilst near to them, will be much more difficult for those who have to travel.

Brides and grooms are entitled to specify a child free wedding, but must recognise that it may not be possible for a percentage of guests to attend.

Of course it would be great if it could be accomplished easily as it’s family, but it can’t. You have offered an alternative that works for your family. You are not causing rift if they don’t accept that- they are.

In fact, it isn’t really a wedding as they’re already married. It’s a big party with a ceremony and posh frocks.

Im sure the £11K can be spent elsewhere.

DH can tell his DM that everyone will come if she is willing to pay for it. NB if that conversation does happen and she agrees, I would get her to buy the plane tickets or give you the money up front.

They are being absolutely ridiculous. Absolutely fair enough have a childfree wedding, but they have to accept that childcare is an issue anyway, and a massive issue if the wedding is abroad!

Suggesting your mum flies out to stay?? They need to get a grip and realise their wedding is not that important (I’m not saying it’s not important, I’m saying it’s not important enough to make this request of guests).

Just say it's not in your family budget to spend £11,000 on anything, nevermind a daft party.
Husbands relatives can tantrum till their hearts are content, it's fine.