A close-knit brother and sister are approached with a request for a 'consciousness survey' that involves lewd questions. Even the innocent sisters think it might be okay since it's their big brother, so they start playing with his dick. It started as half-joking fun, but the sister's curiosity escalates. Although they can't have actual sex because they're siblings, they practice by having intercourse without penetration. Before they know it, his penis slips into her virgin pussy, now soaked and ready.
