For A Quarter

One day a husband was leaving for work and he tells his wife if you have any sex with someone I will rip your pubic hair out. He leaves and she gets horny, and asks a black guy to have sex with her. He says for a quarter and says lets go up stairs. He says for a quarter and she says get in the bed. He says for a quarter and they have sex. Her husband pulls up and the lady says get under the bed. He says for a quarter. The husband comes in and see's she has no underwear on and he says I told you. He see's a black hair and pulls on it and it doesn’t come out of there. He says come out of there you black mother f**ker. The man under the bed says for a quarter.

What is the quarter about?