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: Chapter count includes prologue.