S4, E18: Turk (Donald Faison) and Carla (Judy Reyes) ask J.D. (Zach Braff) to move out to give them some space to rekindle the romance in their relationship. Suddenly homeless, J.D. tries to use the situation to his advantage by asking his girlfriend Kylie (guest star Chrystee Pharris-Larkins, "Passions") if he can stay at her place. Meanwhile, Dr. Cox (John C. McGinley) gets a visit from his high school friend Ron (guest star Michael Boatman, "Spin City"). Dr. Cox and Ron's relationship has always been highly competitive, and just when Dr. Cox thinks he has the upper hand, the discovery that Ron's son may be autistic sends them into unfamiliar territory. Sarah Chalke, Ken Jenkins and Neil Flynn also star.