I’m always distinguishing between “people doing the wrong things”, and “chance of actual danger from the wrong things”.
This is an unfortunate learning opportunity.
If nobody at the school tests positive, and nobody gets the virus, what does it tell us?
It tells us that to people in the same house as a known infected person, who then went to a public event, did NOT spread the virus; maybe the virus doesn’t spread as easily as some people think it does.
If a dozen people get it, it tells us the opposite.
based on the epidemiology of THIS disease I suspect most of the people in that house will get it.
And some of the people at the party will too.
It’s not a (specifically) STD.
Think of the party and dance as ‘one big cruise ship’.