A fellow passed a house with a little red light burning in front, so he
stepped inside. There was nothing in sight, and nothing there but an
empty bare hallway, with 2 doors reading "Over 35" and "Under 35".
He decided to be truthful and entered the door that said "Over 35". He
found himself in another empty hallway, this one with 2 doors that read,
"Over 8 inches" and "Under 8 inches".
Truthful again, he went through the "Under 8 inches" door and found
himself in another empty hall, with 2 more doors reading, "Once a night"
and "Over 4 times a night".
Still wanting to be truthful, he entered the door marked "Once a night"
and found himself back out on the street.
The moral of this story is "Always tell the truth and you'll never get
screwed"