In case you haven't seen this: Somebody posted video of a preschool graduation being held in a classroom with parents present.
The teacher starts by welcoming everyone, and then out of nowhere a little boy shouts, "Shut the [eff] up." The teacher asks him leave, so he says, "No, [B-word]." Then a man comes over and yanks him out of the class. Hope that was his dad, and he'll teach the kid a "lesson".
(Warning: The kid really does say the full F-word and B-word.)