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 further 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 promptly removed a revolver from her purse and shot the mule.

I started to protest over her treatment of the mule when she looked at me and quietly said, "That's once."