Every Night, I Whisper Love to You: The Noble Soldier's Lewd Troubles

Lene, the youngest daughter of a margrave, was forced to marry a rich nobleman by her greedy, older half-sisters despite still mourning the loss of her kind father. Lene had completely given up, but the handsome Duke Ladias, formerly a soldier under her father's command, showed her warmth and saved her from her predicament. "I'll fill you up." His gentle kisses unlocked her lonely heart. Her pure body that had only ever known fleeting love before was rampaged nightly by his sweet whispers and lewd touches. Then, one day, her older sisters discover her whereabouts! Source: MangaPlaza