The siblings' shared secret, a burning lust for each other, simmers beneath the surface of their everyday lives. The brother, a strapping young man, finds himself fantasizing about his sister's luscious curves, while she dreams of his strong, commanding touch. One evening, as they sit together, their legs brush, sending a jolt of electricity through them both. They lock eyes, the unspoken words hanging heavily between them: 'We shouldn't...' 'But we want to...'