Harmless Obsession for the Captivating Male Lead

I possessed the body of the villain’s younger sister who will be punished by the male lead. And I was sure both of us will die to the male lead if my older brother continued his evil ways. So I tried to live quietly while trying to change my evil brother, but the male lead is lying in front of our home? I can’t let him die, so at first I helped him up, but…the male lead’s condition is a bit strange.Wait a minute…did it start already? The male lead’s mana poisoning? There is only one way to calm the enormous amount of mana within the male lead’s body. Immediate physical contact…But that’s the female lead’s job!Aren’t I the villain’s sister? Why me?! What the hell is going on?!“Rose…Please, I need you. Save me…”This is driving me crazy…I can’t turn a blind eye to the dying male lead, and there’s not enough time to find the female lead!…Gosh, I don’t know!Let’s save the male lead first! I’ll help him, then once I find the female lead, we’ll break up! I quietly approached him and we kissed. But as if that alone was not enough, he sighed deeply, then spoke.“Let’s be in a deeper relationship.”“Deeper…relationship?”“Kissing, and other things…”He looked at me sorrowfully. I couldn’t take my eyes off this great beauty when he looked at me in such a somber way. Absentmindedly blinking my eyes, I inadvertently nodded my head. Then he pulled me in and locked his arms. With a dazzling gaze and a bright smile, he spoke.“Rose, you’re my first.”No, I can’t be your first time