My Husband, Who Said He Has Someone Else to Love, Won't Let Me Go!

"Where is my destined bride..?" Countess Seraphina, who lost her parents at a young age and has since taken on the duties of the lord in place of her younger brother, finds herself in a predicament at a ball when she saves Duke Maynard from a difficult situation. This leads to a contract marriage between the two. However, Maynard suddenly declares, "I have someone I love.."? (Source: Ichijinsha, translated)