Best little convent in Texas

A man is driving down a deserted stretch of highway when he notices a
sign out of the corner of his eye.

It reads:
SISTERS OF ST. FRANCIS
HOUSE OF PROSTITUTION 10 MILES

He thinks it was a figment of his imagination and he drives on without
second thought. Soon he sees another sign, which says:

SISTERS OF ST. FRANCIS
HOUSE OF PROSTITUTION
5 MILES
Suddenly, he begins to realize that these signs are for real.... Then he
drives past a third sign saying:

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 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."

The man is led through many winding passages and is soon quite
disoriented. The nun stops at a closed door and tells the man to knock on
this door. He does as he is told and another nun in a long habit, holding
a tin cup answers the door. This nun instructs him to place $100 in the
cup, then go through the large wooden door at the end of the 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