One day Jimmy went down to the pond for a dip, but before he could dive in he spied his teacher.
Mrs.Smith, emerging from nude bathing.
When Mrs. Smith saw Jimmy, she grabbed the nearest object which happened to be an old wooden box and held it in front of her.
“Young man, I know what you 're thinking.” she said.
“And I know what you 're thinking,” Replied Jimmy, “You 're thinking that box has a bottom on it!”