Is it possible to look at things like this in context? It was a dramatic joke. Why do teachers resort to humor like this? They spend a great deal of time attempting to control that segment of the class that reverts to shenanigans out of boredom. You know: the kids that don't want to be there. It is easy to sit there with a straight and somber face and question what thinking leads to this. Ironically, it is the anal retentive,linear thinking, humorless teacher who never takes a risk that ends up keeping their job and makes school a hell for the ones that can't sit still.