One day a man goes to his wife and says "Honey, I've never said anything before, but I need to know: I've noticed that of our seven children, that Jack looks different from the others. Does Jack have a different father than his siblings?"
The wife says: "Yes, I admit it, he does."
The husband says "Who is his father?"
The wife says "You are."
The wife says: "Yes, I admit it, he does."
The husband says "Who is his father?"
The wife says "You are."