The sister, hungry for her brother's cum, takes him in her mouth, her cheeks hollowing as she sucks. He grips her hair, thrusting in and out, his balls slapping against her chin. She moans, the vibrations making his cock twitch. He pulls out, jerking himself off, ropes of cum painting her face and tits, dripping down to her waiting pussy. She fingers herself, mixing his cum with her juices, lost in incestuous bliss.