This is what happend in geography class today:

So we had a test and it was very quite as everyone waited for the last people to finish. The boy in front of me turns to the kid next to him and whispers expelliarmus and points his pen like its a wand. The kid he cast the spell at just looked at him and then dropped his pencil.
It was the funniest thing i´ve seen in a while. The look the boy gave him was perfect.