A blind man walks into a diner...

...and sits down in a booth. The waitress walks up and asks him for his order, and he simply requests a dirty fork from the kitchen. Reluctantly, the waitress brings him the fork, and the blind man promptly puts the fork in his mouth to taste it.
"Mmm... pork chops. Delicious. I'll have the pork chops."
The next day, the blind man comes in and sits down in the same booth and makes the same strange request. Again, the waitress brings him a dirty fork from the kitchen, and again the blind man puts the fork in his mouth.
"Mmm... chicken pot pie. Delicious. I'll have the chicken pot pie."
The day after that, the same blind man comes in and sits in the same booth and makes the same request again. The other waitresses have begun to notice this strange man, and a few of the employees have decided to play a prank on the strange man. When the waitress goes back to get a dirty fork for the man, she first gives the fork to her boyfriend, one of the cooks in the kitchen. He takes the fork, rubs it across his testicles, and hands it back to the waitress. The blind man places the fork in his mouth and makes a confused face.
"What's wrong?" asks the waitress, awaiting his reply.
"...Perry works here?"