A rather well proportioned young lady, Joan, spent almost all of her 
vacation sunbathing on the roof of the hotel.

She wore a bathing suit the first day but, on the second, being a 
naturist, she decided that no one could see her way up there, and she 
slipped out of it for an overall tan.

She'd hardly begun when she heard someone running up the stairs. She was 
lying on her stomach, so she just pulled a towel over her rear.

"Excuse me, miss," said the flustered little assistant manager of the 
hotel, out of breath from running up the stairs.

"The hotel doesn't mind you sunbathing on the roof but we would very much 
appreciate you wearing a bathing suit as you did yesterday."

"What difference does it make," Joan asked rather calmly.

"No one can see me up here, and besides, I'm covered with a towel."

"Not exactly," said the embarrassed little man. "You're lying on the 
dining room skylight."