Revenge on the King of Our House: I Gave My Arrogant Older Sister a 100x-Concentrated Aphrodisiac as Payback, and She Turned into a Slutty Mess—Even I, Her Little Brother, Got Hard. Reina KamikiSTART-255

I hate my big sister. After Dad got laid off, her income became our family's lifeline. From that day on, she turned into the queen of the house, and the rest of us became her servants. I took a dangerous aphrodisiac a friend had left with me, concentrated it 100x, and slipped it to her half as revenge, half as a joke. She went from high and mighty to a desperate, sloppy mess. Even as her little brother, I got hard.