A shy amateur sister, alone with her brother, finds courage in her curiosity. "Please," she whispers, "show me." They sit close, her hand trembling as she unbuttons her blouse, revealing her lacy bra. He swallows hard, his dick tenting his jeans. She smiles, leaning in to whisper, "Your turn." He hesitates, then unzips, his cock springing free. She gasps, her eyes wide, then licks her lips, her hand moving to her pussy, rubbing through her panties. They masturbate together, their eyes locked, their breaths ragged, their bodies aching for more.