I Spent the Night with My Soon-to-be Ex-Husband

"That night, it was a mistake." I was the ill-fated duchess, killed by my husband, the final villain and mastermind in the novel. A weak duchess who couldn't even do her job properly. I planned to divorce him after playing the role of a business-like, show-window couple, but I ended up making a mistake with my soon-to-be ex-husband. "Do you not remember?" But from that day on, the Duke started acting even stranger..? "If you think it was a mistake, let’s check. Do it again." When I came to my senses, I was already in my husband's arms. And when I realized that his embrace, which I thought was always cold, was actually warm, it was too late to turn back in our relationship. ...Husband, why are you so obsessed when we agreed to divorce?