A couple was celebrating...

A couple was celebrating their 
golden wedding anniversary. Their domestic 
tranquillity had long been the talk of 
the town. A local newspaper reporter was 
inquiring as to the secretof 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 on 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 and the mule 
stumbled again. Once more my wife quietly 
said, 'That twice.' We hadn't gone a half - mile 
when the mule stumbled the third time. My wife 
quietly removed a revolver from her pocket and 
shot the mule dead. I started to protest over 
her treatment of the mule when she looked at 
me and quietly said 'That's once.'"