This must be the case, why the hell else would one of my friends give my child a container of gak for his birthday?

It doesn’t matter what she thought he would do with it, surely any parent would know that it doesn’t matter what he would do with it,  that it wouldn’t come off anything.
I commandeered a few minutes and set up the ladder today, to see what I could see. I saw that I had waited too long, but I think it would be a shit to get off at any stage of it’s drying in-ness. I pulled off some of it, and tried to wipe off other parts. I tried to scrape some off, I tried to sponge some off. Now it just looks like the ceiling has blue chicken pox or something.

I must have done something really awful to my friend without realising, or something really annoying for her to do this to me.
I might try to sponge paint one or two of them, and see if it is an obvious cover up. If that doesn’t work, my only option would be to egg my friend’s house.