5x17 "The One with Rachel's Inadvertent Kiss"

Rachel interviews with Ralph Lauren and accidentally kisses her interviewer and prospective boss – Mr. Zelner. Monica wants to prove that she and Chandler are a hotter couple than Phoebe and her new boyfriend. Joey flirts with a girl across the street—in Ross's building, but when he goes to meet her, he instead ends up visiting Ross all the time, due to a miscalculation with the floor number.