Chandler walks into Monica & Rachel's to raid the fridge. Rachel comes out of the shower with a towel wrapped around her waist. Chandler & Rachel scare each other & she drops the towel for a second before snatching the rug off the couch. Rachel is furious and tells Chandler he can not enter the apartment on his own, he has to knock first. She rants while Chandler tries to get a word in. When she allows him to speak, he says, "That's a relatively open weave and I can still see your... nipular area." She storms off, mad & embarrassed. Phoebe & her boyfriend Roger, a psychiatrist, are at Central Perk, talking to Rachel & Monica. She tells him to go away so they can talk about him. The girls love him; they all agree he is cute and sweet. Monica asks her if they are going to have sex on his couch. Phoebe says it will be too weird, because of the Vinyl. Rachel turns to the guys and asks if they need anything. Chandler begins to speak but she cuts him off. Roger asks Chandler if he missed something and he told him "No, she's still upset because I saw her boobies." which ignites Ross with jealousy. Rachel wants the subject dropped. Chandler tells her not to be embarrassed she has "nice boobies." Rachel, even more irritated that the only adjective he used to describe her breasts was 'nice'. Chandler makes a joke which Roger freely analyses to tell him that he has some intimacy issues and uses humour to keep people at a distance. He then proceeds to tell Chandler that he's probably an only child whose parents divorced before he hit puberty. Chandler, amazed and stunned, wonders how he knew all that. Roger says, "It's textbook." Joey enters the cafe with his dad, Joey Tribbiani Sr, who is staying with Joey for a couple of days because he has a job in the city. At Chandler & Joey's apartment, Mr. Tribbiani is on the phone, calling the woman "honey" so Joey takes the phone, wanting to talk to his mom. Only it's not. Mr Tribbiani tells Joey he and his girlfriend, Ronni, have been together for six years. He tells Joey that he is in love with two women. At Monica & Rachel's, Joey is over there, filling the gang in. Rachel walks near Chandler and his gaze goes right to her chest. She notices and asks him to stop staring at her breasts. Telling him, "Did you not get a good enough look the other day?" Ross, trying to be diplomatic, suggests the only way to resolve the issue is for Chandler to show his penis to Rachel. Then the two will be even. Rachel likes that idea, Chandler doesn't. Door buzzer goes off, Phoebe and Roger are downstairs. Monica buzzes them through. Ever since Roger analysed Chandler, he hates the guy. Ross tells Chandler to just deal with it. Cut to Chandler, Ross, & Roger sitting around the table. Ross is upset. He is telling Roger that he is wrong about Ross' fear of commitment and subconsciously choosing a lesbian to marry to fulfil his fear. Roger tells him perhaps he did it because he wanted to overshadow a sibling, which gets Monica's attention. Roger explains that Ross might have wanted to sabotage his marriage so his sibling would "feel less of a failure in the eyes of the parents." Ross is scoffing and Monica is angry, accusing Ross of calling her a failure. Cut to Roger analysing Rachel, who is in tears. Roger tells Phoebe it's time to go to the movie. The two leave, and as Roger exits he tells Monica to go "easy on those cookies, they're just food, they're not love." He shuts the door & Ross & Monica fling cookies at it. Chandler & Joey leave Monica's. They notice a woman sitting by their door, it's Ronni. Inside their apartment, Ronni is talking to Chandler about her job as a pet mortician. Joey's dad enters; he's shocked to see her. She came over to give him his "good hair" which he left at her place. She tells him she has to get going if she wants to catch the last train. Mr Tribbiani tells her he doesn't want her to do that, too dangerous. So he will take her to a hotel. Joey refuses because he wants to make sure they won't do anything. He is playing parent to his father. He tells his dad that the two of them will not be sleeping together under his roof. Joey puts his dad in his room and puts Ronni in Chandler's room. He tells his dad that tomorrow he has to either break it off with Ronni or tell Mom. Later that night, Chandler & Joey share the sofa-bed in the living room. Joey can't sleep, which bothers Chandler. He tells Chandler that he fears that he will end up like his dad one day and cheat on his wife too. Chandler in his best pep-talk yet, tells Joey he knows he will never do what Mr Tribbiani is doing. Joey is happy and snuggles Chandler, which prompts Chandler to say, "Get off!" At Monica & Rachel's, Ronni is knocking on the door. Monica answers & has no clue who she is. Ronni introduces herself as "the mistress" & said that Joey told her to use Monica's shower since Chandler is in his. Rachel sends Ronni to the bathroom, but asks how long Chandler has been in the shower. Ronni tells her "five minutes", giving Rachel a perfect revenge plan. She goes into Joey & Chandler's place, where Mr. Tribbiani is reading the paper. Rachel goes up to the door of the bathroom and says "Chandler Bing? It's time to see your thing." She opens the door, whips back the curtain: it's Joey. They both scream. He runs out in a towel as Chandler comes out of his room. Rachel yells at him for not being in the shower naked. At Central Perk, Phoebe enters. She tells the gang that Roger is inviting all of them to dinner. Chandler laughs. Phoebe notices no one is thrilled and wants to find out why. Rachel tells Phoebe that they just hate him. Back at Chandler & Joey's, Joey tries to turn the sofa-bed back into a sofa when someone knocks on his door. It's his mom. He freaks out. She tells him she came to give him a bag of groceries and then she slaps him on the ear. Turns out she knew about her husband's affair and she is fine with it. She slapped him for making his dad think he had to choose. She tells Joey, "I mean, it's nice, he has a hobby." She asks Joey if he saw the mistress. Joey tells his mom that she is ten times prettier than her & could take her down in a fight anytime. Phoebe & Roger are at Central Perk. He notices something is wrong with Phoebe. He pats his leg, letting her lie down, resting her head in his lap. She tells him the truth, that her friends don't like him. She likes him though. Roger tells Phoebe he isn't surprised because of the "dysfunctional group dynamic" of having "co-dependant, emotionally stunted, sitting in your stupid coffee house" personas. Cut to Monica & Rachel's place. Monica & Rachel can't believe that Joey's mom is allowing her husband to have an affair. Joey has finally has let go of the situation, allowing them to make their own mistakes. Rachel tells the group in a few more years they will become them. Chandler says that will either make him an "alcoholic blond chasing after twenty-year-old boys, or I'll end up like my mom." Phoebe enters, a little depressed. She broke up with Roger. They act sad. Rachel asks what caused the break-up and Phoebe says he is a good sweet guy, but she hates that guy. At Monica & Rachel's, Phoebe reads the paper as Joey enters. He wants "boobie payback" and goes into the bathroom, expecting to see Rachel naked. We hear him scream before coming out, closely followed by Monica in a towel. He leaves. Monica enters Chandler & Joey's apartment, ready for revenge. She sneaks up on the shower door saying, "Hello Joey." She whips the curtain back to reveal Joey's dad, naked. She whips the curtain shut in horror.