Min-hwan, who lives with his brother, was lovers with his youngest sister-in-law. The sex continued even after she married his brother. Eun-hye, who is seeing elder men behind her boyfriend’s back, goes to Min-hwan’s house one day, and is surprised to see Min-hwan’s brother. The elder man she’s meeting in Min-hwan’s brother.

Hwa-jeong and Geon-woo are getting married soon. Geon-woo introduces his friends, Jae-kyeong and Yi-soo, to Hwa-jeong. After a few drinks, everyone goes to Yi-soo's house for a second round. The party ends late at night and Jae-kyeong, who is a lightweight, staggers to the bathroom. He then mixes up the rooms and falls asleep in the room Hwa-jeong is sleeping in. By accident, Jae-kyeong ends up sleeping with his friend's bride.