At their local bar Carneys, the three guys meet and begin discussing the Chris' most recent date. When Nick finds out this was his fourth date with this woman, he complains that Chris never tells him anything. Chris admits that it's because Nick manages to get in his head by finding ridiculous faults with all the women he dates. Nick retorts that he's simply looking out for him, and that the last time he let him be, Chris ended up marrying Sheila, having a baby, and getting a divorce. Touche. An alarm on Chris' phone reveals that it's Gary's wedding anniversary, which Gary completely forgot about. He picks up three measly flowers from the table vase and, in a panic, run outs of the bar to find Marny.
Gary rushes into the apartment and hands Marny the flowers, but he realizes that she too has no clue that it's their anniversary. He is shocked and elated that she forgot. Emily grills Nick about what Chris' new lady is like, but Nick knows nothing except that she's pretty, which is the only question he made sure to ask. Prompted by their daughter, Emily tells her that her first date with Nick, full of sunsets and picnics and carousel rides in Central Park, was one of the most romantic nights of her life.
Chris and Gary stop by Nick's apartment, and Gary gleefully tells the guys that Marny also forgot about the anniversary. All three of them agree that Gary has to pull off the most incredible, romantic night to make Marny feel extra guilty. He'll go down in husband history. Emily comes back into the living room with her laptop open to Jennifer Thomas' Facebook, the woman Chris is dating. Chris shows her profile page to Nick, ready for any critique he may throw at him. Nick has only one; he's already dated Jennifer Thomas.
Seeing as they only went on a few dates and never slept together, Chris decides not to let this fact bother him and invites Nick and Emily over for a barbeque so that they can meet Jennifer. When Chris returns to his apartment, he finds Sheila there, who used her emergency key because she didn't feel like showering at the gym. It turns out she's also gone through Chris' emails and demands to meet this Jennifer, since she'll be spending time with their daughter. Meanwhile, Marny returns to her candlelit apartment to find Gary looking dapper in a suit, offering her a glass of Prosecco. She feels terrible that she forgot their anniversary, even worse when Gary hands her a pair of beautiful sapphire earrings. Gary is milking this for all he's got.
The following morning, Nick and Emily run into Gary at the convenience store. With Chris' upcoming barbeque, Nick worries about him and Jennifer. He assumes she's probably still head over heels for him, considering she hasn't gotten married since they've dated. When Chris and Jennifer also end up at the store, it turns out Jennifer has no idea who Nick is. He tells her they've dated, but this doesn't spark her memory. Nick is stunned, and embarrassed.
Marny continues to treat Gary like a king, giving him an amazing massage and ordering him a 50-inch plasma screen. Later that night, everyone is gathered at Chris' apartment for dinner, with everyone still cracking jokes about Jennifer not remembering Nick. Marny receives a phone call from her credit card company regarding recent activity and realizes Gary purchased the earrings and other anniversary gifts on the day of, not months in advance, like he said. Marny is heartbroken that Gary not only made up a huge lie, but also purposefully made her feel terrible on their anniversary.
All through out dinner, Nick is working really hard at making Jennifer remember him. She finally remembers him as "green Vespa guy" and recounts how he took her on a "corny" date in Central Park, exactly like the one Emily was talking about previously, moment for moment. Emily is devastated that what she thought was a romantic and spontaneous date was actually rehearsed and pre-planned.
Left alone in the midst of the arguing couples, Jennifer and Chris begin to get comfortable until Sheila bursts in and interrupts them, looking for her phone. Apparently she has more than one key to the apartment. Gary and Marny end up making up, laughing about how similar they are and how well they work as a couple. Elsewhere, Nick takes his entire family down to the carousel in Central Park, and tells Emily that even though he's taken other girls on dates here, Emily was the last girl that he came here with. He then pays the security guard to let his family take a ride on the carousel.
While Chris is trying to get Sheila out of his apartment, Jennifer ends up leaving first. Chris stands up for himself and tells Sheila she cannot keep getting in the way of his life. She agrees, tells him that she just wanted to make sure that Jennifer was a respectable person and gives Chris back his key. Walking down the hall, she reveals she has more copies of it anyway.