Percy Weasley stuck his head through the door, looking disapproving. He had clearly gotten halfway through unwrapping his presents as he, too, carried a lumpy sweater over his arm, which Fred seized. "P for prefect! Get it on, Percy, come on, we're all wearing ours, even Harry got one." "I — don't — want —" said Percy thickly, as the twins forced the sweater over his head, knocking his glasses askew. "And you're not sitting with the prefects today, either," said George. "Christmas is a time for family." They frog-marched Percy from the room, his arms pinned to his side by sweater.
—J.K. Rowling, Harry Potter and the Sorcerer's Stone
Is 'you' here used as 'generalized' you, (everyone in general), not specified someone? So George's word implies "We're not going to stay with the prefect, Percy"?