A brother, lost in thought, feels a soft, wet warmth enveloping his cock through his pants. He looks down to see his sister, her eyes locked onto his, eagerly licking and sucking at the fabric, her tongue tracing the outline of his hardening length. She nips at his clothed erection, sending shivers down his spine. She pulls away briefly, her lips glistening, before diving back in, her tongue working feverishly, her hands rubbing and pulling at his jeans, desperate to free his aching cock.