I Married My Ex-Fiancé and His Brother-In-Law on the Night We Broke Off the Engagement.

Core storyline: Being humiliated at the engagement party → Turning around and marrying the male protagonist to counterattack → Making a fake contract marriage → Joining forces to slap all the villains in the face → Uncovering the truth about the life-saving grace three years ago → Smashing the conspiracy to seize power → Running in both directions to consummate HE