A very shy guy goes into a pub on Valentine's Day night and sees a beautiful woman sitting alone at the bar.
After an hour of gathering up his courage he finally goes over to her and asks tentatively, "Um, would you mind if I bought you a drink?"
She responds by yelling at the top of her lungs, "No, I won't sleep with you tonight!"
Everyone in the pub is now staring at them. Naturally, the guy is hopelessly and completely embarrassed, and he slinks back to his table totally red-faced.
After a few minutes, the woman walks over to him and apologizes. She smiles at him and says, "I'm really sorry if I embarrassed you just then. You see, I'm a graduate student in psychology and I'm studying how people respond to embarrassing situations."
The man responds at the top of his lungs, "No I will not pay $200!"