我が家の王様にキ○セク・リベンジ 常に上から目線の偉そうな姉に復讐のつもりで100倍濃縮された性欲増強剤を与えたら、ガンギマリ雑魚マ×コ堕ちし、弟ながら勃起した。神木麗START-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.