It starts out with a man and wife on a vacation for their aniversary. In the begining, the wife is completely faithful and has no intention of straying. But her husband has secretly contacted a black man about seducing his wife on this trip. The couple meets the man innocently and they make friends. The husband continuously finds excuses to leave them alone together to allow his black "friend" a chance at seducing her. Slowly, over the course of the story, she is expertly seduced by the man.

something related is good too.