A lady's sick of her husband's drinking, so she decides to teach him a lesson. She dresses up like Satan, and when her husband walks in from being out all night, she jumps out from behind the sofa and screams.
The guy looks at her and says, "You don't scare me. I'm married to your sister."
A woman yells out, "No, I won't sleep with you tonight, you pig!" Everyone in the bar stops and stares. Completely embarrassed, the guy slinks back to his table with a red face.
After a few minutes, the woman walks over to him and apologizes. She smiles and says, "I'm sorry if I embarrassed you. I'm a graduate student in psychology, and I'm studying how people respond to embarrassing public situations."
To which the guy responds as loudly as possible, "What do you mean $200 for a blowjob?"