Reborn as a Mob, Forced to Fulfill Desires in a Novel I Hated

I died trying to save a dumb kid who was playing with his ball in the middle of the street, completely oblivious to the truck rushing toward him. I managed to save that little prick, but I ended up dying instead. I never thought I would be reborn. And I definitely never imagined waking up inside the erotic novel I had tried so hard to forget. The same one that first made me fall in love with it, only to later twist into something that made me hate myself for ever caring. According to the story, I was reborn as nothing more than a mob character. Not even an extra or a side character, just background noise. Unfortunately, my aunt was anything but insignificant. She was one of the female leads. In the original plot, she was supposed to run away with the protagonist, leave her husband behind, and bear his child, proving she was never infertile. The problem was, I found out about her true identity far too late. To make things worse, I had something called the [Fulfilling Desire System]. It granted me Desire Points that I could spend on almost anything: gaining power, improving abilities, healing, or simply staying alive. And right now, staying alive mattered more than anything else. This new body only had about five hours left before it gave out. Every second I stayed alive cost Desire Points, and the only way to earn them was by fulfilling desires. Which led me straight into my current nightmare. I had already been fulfilling my aunt’s small desires without knowing who she really was. Innocent things. Harmless things. But by the time I finally realized the truth about her identity and the world I had been thrown into, it was already too late. To make matters worse, she looked me straight in the eye and told me her true desire. Quietly, seriously, she asked me to fulfill her deepest wish: to make her a mother. Hearing that, understanding the full weight of my predicament, I knew I was cooked. Thoroughly, irreversibly cooked. Still, fulfilling desires is my duty now. Even if it means going up against the protagonist of this world. Even if it means becoming the villain of this world.