A young schoolteacher came into the classroom on Monday morning to find the word PENIS written in 1inch high letters on the blackboard.
Hurriedly, she took a blackboard eraser, and rubbed the word off the board.
The next morning, she arrived to find the word again written on the blackboard. This time the letters were 2 inches high. Again she wiped the board clean.
This ritual continued all week, until, on Friday morning, the letters were 1 foot tall. She again took the blackboard eraser and wiped the board clean, amid stifled sniggers from her pupils.
At this point, one of the other teachers came into the classroom and asked to speak to her outside.
She came back five minutes later to find the word PENIS again written on the blackboard, in 2 foot high letters, and scrawled underneath was scrawled,
‘The more you rub it. The bigger it gets.’

That is pretty funny.

LOL that is true!!