A couple was celebrating their golden wedding anniversary. Their domestic tranquility had long been the talk of the town. 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 husband. "We visited the Grand Canyon and took a trip down to the bottom of the canyon by pack mule. We hadn't gone too far when my wife's mule stumbled. My wife quietly said 'That's once.' We proceeded a little farther when the mule stumbled again. Once more my wife quietly said, 'That's twice.' We hadn't gone a half-mile when the mule stumbled a third time. My wife took a pistol from her pocket and shot him. I started to protest over her treatment of the mule when she looked at me and quietly said 'That's once.'"