Sister Catherine was asking all the Catholic school children in fourth grade what they want to be when they grow up. 

Little Sheila said, "When I grow up, I want to be a prostitute!" 

Sister Catherine's eyes grow wide and she barked, "What did you say?!" 

"A prostitute!" Sheila exclaimed. 

Sister Catherine breathed a sight of relief and said "Whew! Thank God! I thought you said 'A Protestant'!"