My Wife's Lover 3: Kyung-soo and Eun-ji are married due to their parents' business. Eunji is sad and depressed because her husband's love is not married. Meanwhile, Gyeongsu meets Yeongju without a wife and has an affair. One day, Eun-ji's boiler broke down at home, and she called an AS engineer. He meets Jung Hwan, who was a lover before marriage. The husband goes out of the hotel saying he sleeps at the hotel until the boiler is repaired, and Eunji and Junghwan get hotter after thinking about it...