Swapping, That Dangerous Sex
Plot: Jeong-hyeok happens to meet In-joo, a former karaoke helper, in his neighborhood while being bored with his married life with Eun-hye. In-joo sees Jeong-hyeok's affair and takes advantage of it and asks him for money, but Jeong-hyeok seduces her to swapping because he will give her more money