Since their parents were away from home for a long time, the brother and sister have always been close, supporting each other. The older sister, who just turned 20, has an unusual affection for her younger brother. She also has a strong sexual desire, and spends her days masturbating while thinking about her brother. Finally, unable to resist, the older sister gives him an aphrodisiac and crosses the line into an incestuous fuck! Then, the younger brother tells her he has a girlfriend... Driven mad by jealousy and sexual desire, the older sister gives him more drugs and falls...