Koushaku Fujin wa Nigeru Otto to Ikiru Sekai ga Chigaisugite

Mellie never fooled herself into believing she was more than a mere burden. Since childhood, she had been a leech to House Felton who relied on her mother’s friendship with the former Duchess Felton. Even so, it was inevitable that she came to harbor feelings for her most cherished playmate, Young Master Edric. But things start to change when Edric gets engaged. The former duchess begins treating her coldly, and her childhood friend insists that she remains by his side forever. Mellie has never had agency over her own life. But surely Edric has her best interests in mind, right...?

(Source: Tappytoon)