S4, E13: J.D.'s (Zach Braff) ego gets in the way of his learning when Elliot (Sarah Chalke), his Co-Chief Resident, continually outperforms him with their patients. Meanwhile, Turk (Donald Faison) makes light of his diabetes by inventing a guessing game of his insulin levels with the nursing staff, leaving Carla (Judy Reyes) flustered. Elsewhere, the Janitor (Neil Flynn) feels rejected by his secret crush Elliot, when she runs off quickly from their "coffee date." Assuming his nice dress attire scared her off, he makes up a story that he was dressed to impress for his a capella band practice which leads to Elliot requesting an impromptu performance. Ken Jenkins and John C. McGinley also star.