A man was looking for a place to sit in a crowded university library. He asked a girl: "Do you mind if I sit beside you?"
The girl replied, in a loud voice "NO, I DON'T WANT TO SPEND THE NIGHT WITH YOU!"
All the people in the library started staring at the man, who was deeply embarrassed and moved to another table.
After a couple of minutes, the girl walked quietly to the man's table and said with a laugh: "I study psychology, and I know what a man is thinking; I bet you felt embarrassed, right?"
"The man responded in a loud voice: "$500 FOR ONE NIGHT? ..... I`M NOT PAYING YOU THAT MUCH!"
All the people in the library looked at the girl in shock.
The man whispered to her: "I study law, and I know how to screw people."