Hidden behind the heavy drapes, the sisters' bodies press together, their breathing ragged as they listen to their parents' muffled voices downstairs. The brunette's hands roam, cupping her sister's full breasts, teasing her nipples through the thin fabric of her nightgown. The blonde gasps, arching into her touch, her own hands reaching between her sister's thighs, finding her wet and ready. They grind against each other, their panting growing louder, more urgent, until they're consumed by their forbidden passion.