Bursting into the bathroom unannounced, the stepbrother finds his sister in a compromising position - legs spread, fingers buried deep in her wet pussy. Instead of apologizing, he joins her, his thick, hard cock in hand. They argue, but the tension quickly shifts to something more carnal. She strokes him, feeling his length and girth, before taking him into her mouth, her inexperience evident in her eager, sloppy sucking. He responds by fingering her, finding her clit and rubbing it until she's writhing with pleasure. Their fucking is intense, their bodies slapping together, their moans echoing in the small space, until they're both left panting and satisfied, their taboo act complete.