In the dimly lit hallway, a curious sister finds her brother's door ajar. Her eyes widen as she sees his massive cock in his hand, a glistening bead of pre-cum at the tip. Intrigued and forbidden by the sight, she silently enters, kneeling before him. He looks down, surprise flickering across his face, but she's already taken him into her mouth. She sucks hungrily, her tongue swirling around his shaft, while he grabs her hair, guiding her head. Their eyes meet, filled with lust and taboo, as she takes him deeper, eager for his hot load.