In the dimly lit bedroom, a curious sister, enticed by her brother's late-night activities, tiptoes in, finding him stroking his rigid cock. Her eyes widen at the sight of his throbbing, untouched manhood. She hesitates, then tentatively reaches out, wrapping her small hand around his shaft. He freezes, then relaxes as she explores, her touch sending waves of pleasure through him. She leans in, her innocent breath ghosting over his cock before she tentatively licks the tip, tasting pre-cum. He groans, and she smiles, feeling empowered. She takes him into her mouth, her inexperience evident but her enthusiasm undeniable.