A Scotsman and an Englishman

A Scotsman and an Englishman were sitting around talking one afternoon over a beer.
After a while the Englishman says to the Scotsman , "If I was to sneak over to your house and shag your wife while you were off fishing, and she got pregnant and had a baby, would that make us related?"
The Scotsman 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 being related, but it would make us even."

Is that a joke or a quote from :jbs: :confused: