Secret: Bad Relationship (2023)

Yoo-na’s husband, Joon-mo, is having an affair with a young and pretty woman, So-jeong. One day, a young courier delivered a package to Yoo-na’s house. Coincidentally, the delivery man is Hyeon-cheol, the younger boyfriend she used to date in the past. At first, the ex-couple avoids each other’s eyes, but Yoo-na can’t help but remember the taste of her ex-boyfriend’s stuff, so she seduces him and secretly becomes a sex partner.