A seventy-five year old guy, his hair is completely white, marries a twenty-two year old girl, and she gets pregnant. Nine months later, he walks into the Maternity Ward. He says to the nurse, "Well, how'd I do?"
The nurse says, "She had twins."
He says, "Heh, heh, heh...well, I guess that goes to show, that even if there's snow on the roof, there can still be fire in the furnace."