Stepbrother helps sister with date

Belle has a first date on a beach. She asks her brother for help on which bathing suit to wear. He agrees to help, but then whips his dick out. She says he's so weird because that's her stepbrother. He says that she'll really be able to tell if the bathing suit "works" or not if he gets hard. They play fight until his dick slips in and they just go with it until he cums inside of her.