Season 1: Episode 22: The One With The Ick Factor
Monica gets involved with a guy she thinks is a college senior, only to find out later that he's a senior in high school. Phoebe fills in as Chandler's assistant and finds out none of his co-workers like him since he got promoted. Ross gets a beeper so he can be alerted when Carol goes into labor, but he keeps getting calls for a male prostitute who has a similar number. Rachel has sexual dreams about Chandler, and then Joey and Chandler, and Ross is jealous... until she calls out his name while she sleeps. At the same moment, his beeper goes off for real, and the whole gang rushes off to the hospital.