Tevya was getting very old but he still had an eye for the ladies. So on his 92nd birthday he decided to indulge himself and scheduled a session with an escort.

She arrived and found Tevya in bed naked, and his manhood limp. She looked at him and said,

"Honey, I'm good but I don't think I'm that good."

"Not to worry," he replied, "my doctor gave me a special implant that will make my penis large and hard. All I have to do is snap my fingers."

So he snapped his fingers and his dick snapped to attention. He snapped again and it grew. Each time he snapped his fingers his penis got even bigger until it was the size of a horse.

She watched all of this. First with amusement, then amazement, and finally with horror. "That's way too big. I can't do anything with that."

Tevya said, "Wait. The doctor gave me a fail safe. When I clap my hands it reduces in size." At which point he clapped and it shrank a little. Each time he clapped it got smaller.

"OK," she said, "but can you handle the physical exertion?"  

He smiled and told her to "Climb on and see."

So she straddled him with his cock deep inside her, and suddenly he began alternately to snap his fingers and clap his hands and sing,  

"If I were a rich man, ya da dee da dee da ya da da da dee da dee da dumb....."