He's not exactly sure what's happening on his face, but it's some mixture of surprise and indignation. "She did not!"

He straightens, then stalks forward as quickly as the piles of books on the floor will allow him and grabs a fistful of the guy's hoodie. He yanks him back out of the stacks and towards the door a few steps before letting him go. Who the fuck is this that he thinks he can annoy him with a stupid flashlight app and use Sunshine against him? She's obviously busy, or she would have come over earlier, which means that this guy is lying to him. "We're closed. Get out."