"Sisters of St. Francis" joke

A man is driving down a deserted stretch of highway when he notices sign out of the corner of his eye. It reads: Sisters of St. Francis House of Prostitution, 10 Miles.

He thinks it's a figment of his imagination and drives on without second thought. Soon he sees another sign, which says: Sisters of St. Francis House of Prostitution, Next Right.

His curiosity gets the best of him and he pulls into the drive. On the far side of the parking lot is a stone building with a small sign next to the door reading: Sisters of St. Francis.

He climbs the steps and rings the bell. The door is answered by a nun in a long black habit who asks, "What may we do for you, my son?".

He answers, "I saw your signs along the highway, and was interested in possibly doing business."

"Very well, my son. Please follow me."

He does as he is told and another nun in a long habit, holding a tin cup, instructs, "Please place $100 in the cup, then go through the large wooden door at the end of this hallway".

He gets $100 out of his wallet and places it in the second nuns cup. He trots eagerly down the hall and slips through the door, pulling it shut behind him.

As the door locks behind him, he finds himself back in the parking lot, facing another small sign: Go in Peace. You Have Just Been Screwed By The Sisters of St. Francis. Serves You Right, You Sinner!