MIAA-300 The virgin younger brother, genuinely taking his sister's provocation, doesn't notice he's climaxing and continues with explosive piston thrusts. Kirina Oka

Erina teased her unpopular younger brother as a joke. Mistaking the joke for a genuine invitation, the virgin brother immediately penetrated his sister right after their parents left. Although Erina reached orgasm from the sheer force, her inexperienced brother didn't notice and continued to thrust wildly. Despite reaching orgasm multiple times due to the relentless pistoning, she was made to cum repeatedly until their parents returned home.