YSN-653 I'm kept by my brother, a stupid but sexually active child. Misumi Rei

Rei, the younger sister, is treated as a sexual toy by her useless older brother who can only think about sex. She's interested in sex, but when it's with her older brother, she's not really in the mood. But when her older brother thrusts into her, her face naturally becomes all slutty and she starts shaking her hips on her own, turning into a cute, naughty little sister.