The Marriage Secret . .

        A couple was celebrating their golden wedding anniversary; their  domestic
        tranquility had long been the talk of the town. "What a peaceful and
        loving couple" was an often heard comment when their names came up  in
        conversation.  

        A local newspaper reporter was inquiring as to the secret of their  long
        and happy marriage. "Well, it dates back to our honeymoon," explained the man.
        "We visited the Grand Canyon and took a trip down to the bottom of
        the canyon on pack mules. We hadn't gone too far when my wife's mule
        stumbled. My wife quietly said, "that's once."  We proceeded a little
        further and the mule stumbled again. Once more my wife quietly  said,
        "That's twice." We hadn't gone a half-mile when the mule stumbled  the
        third time. My wife quietly removed a revolver from her purse and  shot the
        mule dead. I started an angry protest over her treatment of the mule, when
        she looked at me, and quietly said, "That's once."
 
        And we lived happily ever after...