My Ex Is Now My Boss

The male lead personally corrupts the docile female lead—teaching her to smoke and making her his bed partner—only to abandon her under the excuse that "I like pure girls". Five years later, he becomes her boss. She hands in her resignation, claiming she is married with a child. When he finds out she gave birth to his baby alone, he shows up at her door with a paternity test, forcing her to marry him for the child and launching an all-out campaign to win her back.