The air is thick with tension and the smell of sex as the sister, her heart pounding with taboo excitement, takes her brother's hardness between her lips. She's never done this before, but she's seen it in videos, and she's eager to please, to make him feel good. She takes him inch by inch, her lips wrapped tight, her tongue swirling around his shaft. She can feel him pulsing, growing harder as she goes deeper, until she's taking him all the way to the back of her throat, gagging slightly but pushing through, driven by a lust she can't control. Her brother, his eyes closed, his head thrown back, is lost in her wet, warm embrace.