As their friends watch, Gary and Marny play a high-stakes game of the board game Chutes and Ladders. Gary wins the spin, meaning he'll get to go watch the football game with the guys while Marny gets the dreaded chore of taking Clark and Yoda to a kid birthday party today. The boys pop in with the news that they've somehow destroyed the blinds in the bedroom.
Nick and Emily's daughter Violet brings a framed photo over to Marny and tells her how beautiful she looks in it. Marny's heart melts; she never gets that sort of love from her four boys. She rhapsodizes about having a daughter, of making her up and buying clothes. Gary instantly grows terrified: four children are already too much to handle. He gathers the guys and sprints out, ready to take refuge in watching football.
At Chris' apartment, Gary's still petrified. Chris and Nick tell him to just tell Marny no. He explains that it's not that easy; she knows his weak spots, like wearing one of his dress shirts or whispering in his ear. "It activates my baby-maker," he admits. They encourage him to be firm with her. Resolute, Gary heads off to go pack up his dress shirts so he can hide them at Nick's.
Sheila arrives at Chris' to pick up the baby, hurtling a few insults at Nick and Chris along the way. While Chris sees her out the door, Nick helps himself to a bowl of cereal. Chris returns to the kitchen where he notices Nick eating the cereal and asks Nick if he helped himself to milk from the reusable plastic bottle in the fridge. Oops: it appears that Chris has been enjoying his cereal with a secret ingredient: Sheila's expressed breast milk. Nick's knees begin to buckle at the realization; he makes Chris swear to never tell Sheila.
Nick returns home and confesses what happened to Emily. She's not especially shocked at what Nick did, but she's definitely annoyed to learn that perfect mother Sheila is still breast-feeding. It's just another example of how she makes everyone feel inferior, she says. They're both loathing their upcoming trip to Sheila's upcoming baby CPR refresher class. And there are more problems. Emily reveals to Nick that their daughter, Violet, has resumed an old and nasty habit: stealing. Emily's convinced their girl is headed for jail. Nick calls Violet in and gently reprimands her.
Back at Gary and Marny's place, Marny wonders where Gary's dress shirts have gone. Gary tells her he's sent them all to the cleaners. But Marny's determined. She finds an old, stained shirt and saunters out with an amorous look in her eyes. She puts some serious moves on her husband who does his best to resist. "Hands off the merchandise!" he screams to her. But it's a losing battle. Suddenly Nick appears at the door, ostensibly to return a photo that Violet stole from Marny and Gary's apartment. Gary's relieved and invites Nick to join them. Marny tries to fend Nick off, but finally Gary takes off with him to head upstairs to watch a movie.
At Sheila's CPR refresher class, a rah-rah instructor passes out baby dolls for practice. Chris offers his girl baby doll to Marny, acknowledging that she and Gary are trying to have a girl. But the news of their trying to conceive was supposed to be a secret, at least according to Marny; she doesn't want the guys weighing in on their family planning. Gary tries to backpedal, claiming no one is trying to influence their decisions. The CPR instructor adds (not so helpfully) that if they're looking to have a girl they should try to conceive early in Marny's cycle. Marny storms out, with Gary not far behind, in damage control mode.
At their apartment, Mary and Gary try to talk it out. He's simply overwhelmed with the four kids they have already, while Marny counters that one more wouldn't be so much more work and would fulfill a lifelong dream for her. At an impasse, they decide to try Chutes and Ladders to decide the matter. As they start playing, Marny asks Gary to imagine the situation the other way around: if they had four girls, wouldn't Gary be pushing to have a boy? He considers this for a long moment, then agrees. They decide they'll try for a girl.
At the infant CPR class, Emily can't stand just how superior and smug Sheila is; it's a familiar complaint. The group decides they should have a series of competitions to determine which couple knows infant CPR best. Nick gets down on the floor and does his best in a head to head battle with Sheila, but he's no match. Chris tries to distract Nick while he works, and Sheila aces her CPR. It's no contest.
In their bedroom, Gary and Marny are giddy to get their baby-making on. Just as they embrace, a kid starts screaming outside the door. Someone's managed to wet two beds. They change the sheets and try to get back to business. But now it's the baby who's complaining. Gary texts Chris and Nick to come help. They barge in and spot Gary and Marny with bedroom eyes - and immediately try to kidnap Gary to protect him. Gary explains that he's had a change of heart. The guys shake their heads but get it, leaving Gary and Marny, parents of four, alone to try to become parents of five.
Back at Emily and Nick's, Violet's been caught stealing again. She's got Sheila's keys. Nick decides to tackle the problem head on. They all march upstairs to Sheila's where Violet sheepishly returns the keys and offers an apology. Sheila's surprisingly understanding; she reveals that she herself would steal things at Violet's age. Nick tries to usher everyone out, but Emily feels this is the time for Nick to come clean too. He embarrassingly reveals to Sheila that he accidentally drank her breast milk. Sheila's shocked - and then grossed out. She runs off. Nick feels surprisingly better.