In the quiet of their home, a brother and sister find themselves alone, their curiosity piqued. They start innocently, masturbating in their respective rooms, but the thin walls can't muffle their moans. Caught off guard, they argue, but later, a truce forms. Naked, they explore each other's bodies, the sister's eyes widening at her brother's impressive length. Just as they're about to cross the final line, a sudden noise forces them apart, their taboo tryst cut short.