Is there a punchline?

There really is no telling this fella, is there?


A man lies on his deathbed, surrounded by his family: a weeping wife and four children. Three of the children are tall, good looking and athletic; but, the fourth and youngest is an ugly runt.

"Darling wife," the husband whispers, "assure me that the youngest child really is mine. I want to know the truth before I die, I will forgive you if ..."

The wife gently interrupts him. "Yes, my dearest, absolutely, no question, I swear on my mother's grave that you are his father."

The man then dies, happy. The wife mutters under her breath: "Thank God he didn't ask about the other three."

source: http://www.jokes4us.com/peoplejokes/manondeathbedjoke.html