Two men drove to a gas station for a fill-up because they heard about a contest being offered by the station to patrons who purchase a full tank of gas.  When they went inside to pay, the men asked the attendant about the contest.

    "If you win, you're entitled to free sex," said the attendant.

    "How do we enter?" asked the first man.

    "Well, I'm thinking of a number between 1-10, if you guess right, you win free sex."

    "O.K. I guess 7, " said the first man.

    "Sorry, I was thinking of 8," replied the attendant. "Come back soon and try again"

    The next week, the two men returned to the same station to get gas. When they went inside to pay, the second man asked the attendant if the contest was still going on.

    "Sure," replied the attendant. "I'm thinking of a number between 1-10, if you guess right. You win free sex."

    "2" said the second man

    "Sorry, I was thinking of 3," replied the attendant. "Come back soon and try again."

    As they walked back to the car, the first man said to the second man,"You know, I'm beginning to think this contest is rigged."

    "No way," said the second man. "My wife won twice last week."