AIBU to agree my sister’s friends may want child-free girls’ nights?

Totally agree with you. Clearly her friends do too.

I assume you didn’t talk to them though?

100%

Yep fully agree with you.
Your sister clearly has main character syndrome, and it seems that she's bringing her kid up to be the same.

Make sure you don't suddenly turn into a doormat by acquiescing with her to keep the peace- hold your nerve.

You're right but overstepped with your "gentle suggestions." Her friends are adults who didn't need you speaking for them. Now you're the bad guy.

Oh God yes. DN’s presence as an honorary member if the group would seriously piss me off, to be really honest,

You're absolutely right.
Only the strongest maternal blinkers would make someone think an eight year old dancing was entertainment.

As a one off fine but I’m with you, a girls night in doesn’t involve kids (asleep in bed is fine)

Im 100% with you. She will come to understand you don't know the friends and they came to their own conclusion. Then maybe she can fall out with the friends too for a while! Hopefully she will realise her views are different to theirs and come around to accept that and put the whole silly thing behind her. The choosing to not talk to you part is very childish.

Well I’d put her straight on that aspect at least.

The only thing more boring than your own child’s dance routines is someone else’s child’s dance routine.

You are in the right, both in trying to to point that out to your sister originally - especially as you offered to have your niece for the night - and now. I do this with friends. If the kids appear for ten min at the beginning and say hello, then disappear to bed and we don’t see them again, that’s fine. But why would I leave my own kids to spend time with someone else’s? It’s either a family get together with all kids or an adult get together with no kids. The reality is that no one finds your kids adorable and interesting the way you do yourself.

Of course YANBU, I can't imagine anything worse than spending a girls night in watching some kid doing her Taylor Swift moves.

However, no good deed goes unpunished. Leave your sister to sort it out.

Nothing. Fucking. Worse.
sounds like her friends have nipped it in the bud though. A quick hello, goodnight , is permissible but otherwise absolutely not, and dance routines ffs,if people want to watch that shit they do it at home with their own children under duress. It could only be worse if she gave them a recorder recital.

Omg! My friend did this to me on a months in advanced night in with cocktails and karaoke. There were 6 of us and she bought her 9 year old twin girls. She said it was only for 2 hours then her husband would he collecting them so we all made an effort, made them cocktails and listened to their signing and showing off thinking it was only till 8.30pm. Lo and behold as it approaches she said they were having too good a time so we’re staying. Absolutely ruined. She also was very unhappy when we told her it wouldn’t be happening again. We all have kids 5-12 and are grateful for the break away!!

Mocktails!!! We made them mocktails just to be clear

Oh gosh your sister has screwed this one up. My daughter own children had a phase of doing routines and it’s bloody painful as a parent who loves them dearly. Her friends will have been wanting to put pins on their eyes.

Oh dear. I think the first time the guests assumed it was a one off and she couldn't get a sitter so didn't mind. Sister assumed they liked it and it had been a huge success. Now they've had to tell her this should not be repeated if possible and she's offended.

Don't say anything else except that you didn't say anything to the friends and that you don't want to upset her so won't say anything else about it.

I used to be in a book group where we took turns to host. My kids were right show offs when they were younger but I'd only let them come in for a few mins as people were arriving to say hello and nick some of our crisps and would then ask DH to keep them (and himself) out of the way. He'd sometimes moan that "they like seeing everyone" because he was a bit lazy about keeping them amused and getting them ready for bed but I would firmly say "well this is an adult group and everyone does not want to see THEM."

Yes this
I host in turns and have kids, many of my friends don’t yet (but they do want them asap which maybe changes things?), so my DD says hello/quick chat and then goes to bed. I tend to host after 7pm so I can be uninterrupted but wouldn’t expect my friends to be knobs about it either.
When I go to my other friend who has 5 kids ranging 7-18, they are often awake and it doesn’t bother me at all! We just mind what we are talking about if they are right there and when not, chat away!

This has happened at my craft group evenings - someone brought their high school aged daughter along one evening and now lots more crafters are bringing their primary aged grandchildren.

Hate the group dynamic now - considering taking my preschool twin grandchildren to see how that will go down.

Some things should stay 'adult only' - I look forward to socialising with friends: especially as I do need a break from 'child company' as I look after both my daughters' children on a daily basis.

maybe you should have made them cocktails. Mother definitely wouldn’t have brought them again 🤣

Oh god your sister had called foul of a classic blunder!

No one else wants to watch your child putting on a show. No one wants to see them singing and dancing on their adult evenings.

Maybe if DN had gone quickly to bed her being there would be fine but of course they didn’t want a child joining their adult evening, when they’ve all sorted babysitting themselves.

A one off they perhaps put down to no childcare. The fact she was repeating it made it clear that she never has any intention of having a child free night. She needs to think how she might feel if she went round theirs and their kid stayed up chatting when perhaps she wanted to have a child free night.

There was a thread a while back about someone who insisted on bringing their 8 year old to girls' nights out despite having a partner . This sort of thing needs to be stamped out