"Oh! My uncle has one of those!"
Huh? I was thinking... I turned and looked quizzically at him.
"Yeah! Automatic Pea Gun! My uncle's got one of those!"
Predictably, the term "pea gun" was heard by some of the youngsters as "pee gun." Gasps and giggles rippled through as a room full of ten year-olds with ticklish insides considered their various visions of a "pee gun...." After a fashion, I restored the lesson's momentum, and the kids brainstormed dozens of examples of onomatopoeia.