Fanjo you still haven't answered the question though.
Do you think that NT siblings of children with SN deserve to be as protected than children with SN? Or is it that, because they are NT, they have so many advantages that it doesn't matter?
More widely, the child whose b'day it is has their own life and their own difficulties. They might have an abusive parent, one that is alcoholic, siblings with their own issues, escaping from a house with domestic violence, who knows?
Don't they need to be protected too? Shouldn't we take that into account and let them have ONE day (or rather a couple of hours) just for them for once?
When I look at my dcs, I see the needs of both children, the ones who has some SN and the ones who is NT but is struggling to live in a house where everyone has to walk on eggshell.
My dc with SN deserve to be treated nicely but so do the one who is NT.
It is heart breaking when all the people who were supposed to come to his b'day cancelled at the last minute (something else 'better' came along). That's the one with SN.
It would be heartbreaking to see my NT dc having to deal yet again with a child whose behaviour is hard to deal with, on his b'day, at THE one time he should have been happy and relaxed.
The NT child or the one with SN isn't more deserving there. Whatever choice you are making, it is going to hurt someone.
But I refuse to say that the hurt that the NT child would have is somehow less important than the one from the child with SN (Note: when this happened to my own dc with SN, he actually wasn't bothered.... So the 'hurt' woud have been more about me rather than about him iyswim)
Last comment: I have never not invited a child because of behaviour problems. The problem was solved by NEVER inviting the whole boys group.