In His Obsession, She Belongs - Dramabox

Fiona Joel has been engaged to her fiancé for four years. During that time, he has slept with dozens of women. Although Fiona pretends to be hurt by his infidelities, she secretly feels relieved, knowing she will marry into a wealthy family without having to fulfill the role of a devoted spouse to a man she doesn't even like. To even the score, she spends a night of passion with a stranger while waiting for the elevator, and the mysterious man accepts.