The first sex education classes were held in the fifties. Naturally, some teachers were embarrassed and used only very carefully chosen words.
In one class, the teacher was explaining the anatomy of the male genitalia. He said, "The human male testicles are about the size of Plover's eggs."
A female voice from the back quipped, "Hey... Neat!!! I've always wondered how big Plover's eggs were."
Stolen from: Phil of Phils Phun