"Worst Sound" joke

There was 3 old men sitting by a pool talking about old times. One of the men asked the other two what was the worst sound they ever heard.

The first old man said, "Well I was in Africa once and had a herd of wild elephants come in my direction and I had no place to hide."

The second old man said, "I was a pilot in the air force and was flying over the ocean and the engine on my plane was making bad noises like it was going to quit."

The third old man who had asked the question said, "I have the worst one of all. I was seeing this woman and her husband came in on us while we were in the bed together. I jumped up and ran and jumped out the window."

The third old man paused and the other two men asked, "Well, what was the bad sound?"

The third old man replied, "Just a minute. This is hard for me to retell."

After a short pause he said, "Okay, I jumped out the window and the woman's husband grabbed me by the balls! So there I was, hanging by my balls, and the worst sound I ever heard happened. It was the sound of a man trying to open his pocket knife with his teeth!"