S5, E10: Love is no laughing matter -- Mandy Moore guest stars -- J.D. (Zach Braff) becomes annoyed that new girlfriend, Julie (Mandy Moore), doesn't laugh, but rather tells him when things are funny. Afraid that he is going to screw up yet another relationship, Elliot (Sarah Chalke) encourages J.D. to start saying his feelings out loud and Turk (Donald Faison) tries to use his psychology background to fix the issue. Meanwhile, Carla (Judy Reyes) is upset when the Janitor (Neil Flynn) refers to the new nurse as a 'hot young Carla,' increasing her growing concern that she is too old to conceive. John C. McGinley and Ken Jenkins also star.