In the dim light of the den, a sister finds herself kneeling before her brother, his hard cock twitching in anticipation. She looks up at him, her eyes filled with a mix of fear and desire, before leaning in and taking him into her warm, inviting mouth. She sucks him with a hunger she's never known, her cheeks hollowing out as she takes him deep, her tongue swirling around his shaft, tasting every inch of him.