Unbeknownst to their parents, these siblings have developed a secret, forbidden language of lust. The room echoes with wet, smacking sounds as the brother's cock disappears into his sister's eager mouth. She relishes the feel of him, the taste of his pre-cum, and the power she holds over him. She takes him deep, her eyes watering as she struggles to take every inch, her tongue expertly teasing his shaft. He clutches her head, fucking her mouth with abandon, his body tensing as he cums, his hot seed spilling into her waiting mouth, filling her, dripping down her chin, a testament to their shared, sinful secret.