In a modern world, Lee Yunhui was an ordinary housewife and wife like any other. However, her husband had a secret fetish he couldn't tell anyone: he got excited by watching his wife be with someone else. Yunhui initially refused repeatedly and scolded him, saying it was wrong, but after her husband's persistent requests and pleas, she decided to grant his wish just once. And on the long-awaited day, Yunhui meets Guest, whom her husband brought along, for the first time.