Minjae and Jaehyun, who are in their 5th year of dating, love each other as much as ever. However, Jaehyun hasn't been able to climax through ordinary sex for some time. One day, they do it in the emergency staircase because Minjae tempted Jaehyun, and Jaehyun feels it so damn much... When he has this new kind of sex with Minjae, Jaehyun is overcome with an intense pleasure that he has never felt before. But he wonders, is it okay to become so perverted?