MIAA-271 The virgin brother, who took his sister's provocation seriously, doesn't realize he's cumming and explodes with a piston, Urara Kanon.

Urara teases her unpopular younger brother as a joke. - The virgin younger brother took the joke seriously and misunderstood that she was inviting him, and immediately inserted his cock into her sister right after their parents left. - Urara climaxes with such force that her younger brother, who is not used to women, ignores her and continues to shake his hips. - The pleasure of the piston continues even after climaxing, causing her to climax over and over again, and her resistance becomes futile as she continues to cum until her parents come home.