"The One With Phoebe's Husband" is the fourth episode of the second season of Friends, which aired on October 12, 1995.
Rachel receives a visit from a handsome blond guy looking for Phoebe. As Phoebe's not home, she offers to leave a message, and he tells her to tell Phoebe that her husband stopped by.
When asked for an explanation, Phoebe spills it out that she had married Duncan, but the only reason she did it was to help him, a Canadian gay ice dancer, get a green card. Monica reveals to everyone that when Duncan left, Phoebe was crushed to the point when she ate a cheeseburger. Phoebe reveals to the guys that the underwear on the telephone pole is hers from having sex with Fun Bobby on the terrace, which only Chandler knew about. Monica blows Chandler off by revealing that he has a third nipple, which the guys find really weird. Chandler reveals to everyone that Joey was in a porno movie (albeit not in a sexually engaging role, he played a copier repairman who walks in on a couple having sex on it).
Phoebe dresses up to meet Duncan at Madison Square Garden, whilst the others go to Ross'. She's thrilled to see him. When she asks him what he wants, he requests a divorce from her. When asked why, he reveals the "shocking" news to Phoebe that he is actually straight. The truth freaks Phoebe out, and she finds it hard to accept his sexuality, especially when he reveals that after college parties, he would often wake in bed next to girls. She gets over the shock pretty quickly when he tells her that his brother is straight.
Ross seeks sexual advice from Rachel, as he and Julie are not having sex. Rachel takes the opportunity to make him put sex off by making him believe that girls find it sexy to be with a guy who doesn't want to have sex. Ross thanks Rachel for the advice, and also lets her know that he talked to Joey for the same advice he asked from her, and following this conversation, he has in mind to have sex with Julie that night. Chandler happens to have the porno movie Joey was in. Everyone watches the movie, but Rachel doesn't want to call it a night, so she engages Julie in a long conversation in the hope of putting her off sex with Ross. Eventually, everyone leaves, leaving Ross in the hall with Rachel. In a last, desperate move, she freaks him about about his first time with Julie and how a lack in performance can mar the whole experience, and she starts to describe to him the situation she would like to be surprised with. The heat is apparently coming up to Ross, but he thanks her and leaves her in the hall to have sex with Julie - twice.