A guy asked a girl in a university library: "Do you mind if I sit beside you?"
The girl replied with a loud voice: "I DON'T WANT TO SPEND THE NIGHT WITH YOU!"
All the students in the library started staring at the guy; he was truly embarrassed.
After a couple of minutes, the girl walked quietly to the guy's table and said: "I study psychology, and I know what a man is thinking. I guess you felt embarrassed, right?"
The guy then responded with a loud voice: "$500 FOR ONE NIGHT? THAT'S TOO MUCH!"
All the people in the library looked at the girl who was now in shock.
The guy whispered in her ear: "I study politics, and I know how to screw people."