When the youngest sibling catches her older brother masturbating in the bathroom, her curiosity piqued, she demands to know "who's first?" Summer Reid's hidden camera captures the siblings' intense, secretive encounters as they navigate the complex, forbidden world of incestuous desire. From tentatively exploring each other's bodies to full-blown, raw fucking, their taboo affair is a whirlwind of guilt, pleasure, and insatiable hunger, culminating in a climactic scene that leaves them both spent and craving more.