To not take child to party?

You are absolutely Right. Twins are not just siblings , they need special care and consideration. People who reply to your post should only do so if they have experience of being A TWIN. I expect that not many will. Twins need to be together ALWAYS. Till grown up obviously.

At 3.5 i wouldn't take your son to the same soft play, being left behind while his friends go into the party room is far worse than his sister going to a party without him.
I'd ask someone else to watch your daughter, and have some lovely 121 with your son, doing something else.
It's ok for them to do things apart. It's good for them, providing its handled well.

If i was having a party I would invite both kids, I think the parents are out of order for not doing so.

And in your position I would decline the invite, your own child's wellbeing should come first. They are too little to understand why one is being invited and not the other. I think it's incredibly unkind.

Peachy, you?

First names, not a problem. Surnames, absolutely not.

Glad we cleared that up.

I think i would decline.
But then when they start school I would ask for separate classes and start accepting individual invitations then.

I don’t even believe they’d give out first names never mind full names, nobody said ‘first’ name, they just said names. Given that I don’t believe either first or last would be given I just responded to the previous poster using their hypothetical scenario in which names (unspecified) were given…

Are you feeling ok?

That wouldn't be a GDPR breach in itself as it's inside the nursery (although not really best practice, I'm surprised to hear they do that). General rule of thumb is no more than two pieces of identifiable information should be presented together. So you can have the child's first name and photo alongside each other on their peg, but no surname with it. You could have the child's name and birthday listed on a birthday display, but no accompanying photo and definitely no surname. If the register has their name and surname, it shouldn't have their photo and/or DOB too etc.

They definitely wouldn't be able to send full names out to other parents though, in correspondence which is leaving the nursery premises. That would be a GDPR breach.

Just take DD. It's not fair for her to miss out because the other isn't invited.
You could ask if you could pay for ds to attend but not do the party room bit.
I've had that with multiple parties and siblings have joined for the play

Also how come the 5 Yr old is still in nursery and not in school?

They just said nursery may have provided names of children the birthday child plays with, which could very well have happened (although I really can't imagine the nursery would have listed one twin without the other, so it's more likely it was the child who was asked who he wanted to invite).

The other poster didn't say surnames would be included in a list, you did by suggesting the fact they have the same surname would have been a clue they were twins. I'm just pointing out that a nursery should never publish full names of children so that won't have happened. They may give out first names, but never full names.

God this is a painful read. The twins are 3.5 NOT 5 ffs OP can’t just drop one off and leave!! JFC. I think you did the right thing op

I think it's daft not to ask if you think it's likely the mum doesn't know they're twins. For my child's 4th birthday we were rather grasping at straws as to which nursery friends to ask, our child only gave us a few names, the rest we just asked the nursery for suggestions. (Which he was perfectly happy about.) I absolutely would not have asked one twin and not the othe, but now you come to mention it, I don't know whether there are any twins at nursery. Obviously they will grow until being their own people with their own interests and friends but it's all a work in progress at 3 anyway.

you'd leave your 3 year old at a soft play party with a family you barely know? what happens when she needs the loo? or she can't remember what the people she's with look like? or she just gets bumped or overwhelmed? you think the Mom who's throwing the party is going to sort out a poo emergency 🥰😀, make sure they don't get stuck atop the bog slide, make sure they don't wander somewhere they shouldn't?

The parents probably don't realise they are twins. I inadvertently invited one twin to my ds 4th birthday party. It was another mum friend who said to me, and so I think then invited the other twin. They're 15 now and ds is still close friends with this pair of twins.

I didn't do drop off often as I worked and it was their grandparents who did the nursery run, they were non identical and I just didn't clock they were twins. I had got DS to do a list of who he wanted to ask!

ofcourse they do, but that doesnt mean that every experience has to be something to learn resilience from. esp at that age

Are you a single parent? If not surely the invited twin can go to the party and the twin who isn't invited can do something fun/exciting with their other parent?

Again, not me that suggested names, I just responded to someone who said it.

I didn’t suggest they gave out names, the person I was replying to did.

I'm also a twin and think at 3.5 it's abominable that one has been invited but not the other, especially as they both play with birthday boy.

For parties I've always invited other twin as well, and let people know there's room for siblings if needed.

Yeah, I think they are too young to understand why one of them is invited and not the other. It would be different if they were in different classes because you could say it's only for children who know each other but this would be with their joint friends.

Again, as a twin mum, it stops when it’s easy to do so. Path of least resistance, etc. This kind of parenting approach on its own doesn’t lead to co-dependency. It just leads to more pleasant outcomes. Toddlers are hard enough. Two of them together does often double the difficulty. Sure she could put her foot down and take one but not the other and deal with the consequences. Or skip the party and deal with those consequences. Either way, it’s not going to cement their personalities forever.

Usually starts in year one depending on type of party, how well they know the others and the temperament of child. Ie around 6ish.

So? At what age does it stop? When the OP finally decides to separate them for activities, she’s going to have an awful time doing so.