A brother and sister, alone in the house, find themselves drawn to each other's bodies. The sister, a beautiful woman, catches her brother's eye as she bends over, her round ass on full display. The brother, unable to resist, begins to stroke his growing erection, fantasizing about his sister's curves. She notices, and instead of being upset, she feels a spark of her own desire. They lock eyes, the tension building, as they both struggle with their taboo urges.