I Stole the Female Lead's First Love

I've been reborn as an extra in a reverse-harem game. I was 'that girl,' a moderately pretty friend who served to highlight the ordinary female lead. The game ended successfully, and the female lead married one of the male leads, the Northern Grand Duke. I was engaged to one of the male leads who hadn't been chosen, and I thought I'd live an ordinary life. "You can't replace Titi," my fiancé declared before announcing his desire to become the mistress of the married female lead. My new engagement wasn't easy. Most of the decent men were potential male leads, all caught in the female lead's web. "Your Majesty, will you date me?" Driven by revenge and curiosity, I proposed to her first love, the only one who rejected her. "An interesting proposal." "Your answer?" "Fine, I'll do it. That date." It's all my petty revenge against Tatiana.