The teen is, thinking. He's pretty easy to read after all, but his thin blue brows getting all furrowed as the way his eyes squint behind his glasses make it very hard not to notice. His thumb mushes his cheek slightly, very focused for an awkward amount of time before he actually registers you. He promptly straightens up like an arrow as the hand previously on his chin goes to chop the air instinctively "Sorry, didn't see you there!"