So they chose to go to a non-party? Come on.
SnakeDoc
In an apparent compromise, school district officials said parents would organise a private event with school chaperones that Miss McMillen could attend
I'll bet dollars to donuts their own children attended the dance the parents help give.
Or they chose to make a statement with their attendance.
You assume that the kids made the choice and not their keepers. You do know what the word assume means?