Hatsukoi no Hito to no Hare no Hi ni Reijou wa Uragiri wo Shiru Shiawase ni Naritai node Koushaku-sama no Kyuukon ni Damasaremasen

Synopsis

She was meant to get revenge on her traitor, but now she's completely surrounded by the Duke's obsessive love!? After being dumped by her ex-fiancé because he was a knight, Tiziano is proposed to by the Duke of her dreams. However, on the day of their wedding, she learns that the Duke has a lover... She was meant to get revenge on the traitor, but before she knew it, she was being pampered...!? (Source: Kadokawa, translated)