Gongjangnimui Malsseumeul Geoyeokamyeon

You must never see the duke’s face. After her second husband's death, Lily is forced into a third marriage by her father. Her new husband is rumored to be a monstrous warmonger, but to Lily's surprise, the Duke turns out to be a kind man and husband. There's just one catch... she must never see his face. (Source: Manta) Note: Includes one extra chapter.