Seong-il and Hyun-jung are a couple. Seong-il has a strong interest in sex, but Hyun-jung is growing weary of his constant demands. She confides in a colleague about her husband's persistence. Minwoo, their neighbor who has long been attracted to Hyun-jung, overhears the conversation by chance. He offers to help her with her trash, creating an opportunity to connect. Minwoo then asks his sex partner, Yoon Kyung, to seduce Seong-il. Disguised as a gas inspector, Yoon Kyung visits Seong-il's home and successfully seduces him. Afterward, Seong-il attempts to have sex with Hyun-jung, but...