S3E11 · The One Where Chandler Can't Remember Which Sister

Complete story — includes the ending

Monica and Rachel's noisy upstairs neighbor is excessively charming. Phoebe confronts him about the noise and ends up dating him, making Monica and Rachel uncomfortable when they later hear all of Phoebe's intimate upstairs activities. Rachel is frustrated with her new job of making coffee all day and sorting hangers. When Rachel vents her frustration to Monica at the diner, a customer named Mark mentions a vacancy in his department at Bloomingdale's and arranges an interview. Rachel gets the job, but Ross suspects Mark has ulterior motives for recommending her. A drunken Chandler fools around with one of Joey's sisters, but later cannot remember which one, angering Joey.