Adult Games by Higurashika

At the center of the story is a girl, whose parents were the stars of adult films. It's no secret; they don't hide it from their daughter. Sex surrounded the girl since birth, but she does not want to be like her mother. And when her sex-obsessed best friend, the Queen Bee of their class, begins a naughty social experiment, the MC has to decide what kind of person she wants to be.