I lose my reason when I see my girlfriend's sister Miyu's defenseless big ass in her panties and push her down. Even though she refuses, I promise to just rub it, and when I get her to do a panty rub, Miyu's pussy gets soaking wet through the fabric! As I tease her with my glans, she starts to moan, so I just plunge it in! It's the best feeling to thrust into a shaved, horny pussy while watching a high school girl's bouncy ass! Miyu is so cute that she trembles as she cums, and I end up pistoning her from behind and cumming inside her again and again!