Fair Play?

Bob and Joe were sitting around talking one afternoon over a cold beer.

After a while the first Bob says to the Joe, 'If I was to sneak over to your house and make love to your wife while you was off huntin', and she got pregnant and had a baby, would that make us related?'

Joe crooked his head sideways for a minute, scratched his head, and squinted his eyes thinking real hard about the question.

Finally, he says, 'Well, I don't know about related, but it sure would make us even.'