HOW TO BE SINGLE
NOTE: This spoiler was submitted by Jeremy
The film starts by introducing us to four individual women. Alice (Dakota Johnson) has been in a relationship with Josh (Nicholas Braun) for four years since college, but she has now decided she wants to spend time alone and not be held down in a relationship as she moves to New York City to start her new job. Robin (Rebel Wilson) loves being single and takes advantage of it whenever she can, and this usually leads to her ending up in a stranger's apartment. Meg (Leslie Mann), Alice's sister, is a doctor that has delivered multiple babies but never felt the need to settle down and have one herself. Lucy (Alison Brie) comes off too strong around men, which usually scares them away.
Lucy goes to the bar downstairs from her apartment to use the wifi. She meets the bartender, Tom (Anders Holm), who wonders why Lucy would be single. She uses an algorithm to determine that at least one guy in all of NYC has all the qualities she desires, and she's on multiple dating sites to find the right guy.
Alice starts her job as a paralegal at the firm where Robin works. After work, Robin invites Alice to hang out with her in the city and see what it's like to enjoy single life the right way. The next morning, the ladies wake up hungover in Meg's apartment, along with someone Robin hooked up with. The two then head to work with only 30 minutes. Robin takes Alice through a crazy fix-up routine that she claims she can do in 20...but they're late by 3 1/2 hours.
At work, Meg is left to look after a woman's baby. After spending a few minutes alone with the kid, Meg quickly falls for it and admits to herself that she wants to have a kid of her own.
Robin takes Alice to Tom's bar, and he later ends up hooking up with Alice. She learns that Tom embraces his bachelor lifestyle and has a carefully-planned setup for making sure his hook-ups leave quickly the next morning, such as cutting off water so that women would have to leave and find water for their hangovers.
Lucy is at the bar in her sweatpants, when she is approached by a bachelorette party of old friends. When pressed with the question of her relationship, Lucy awkwardly tries to come up with an answer until Tom swoops in and kisses her in front of the party, to their surprise.
Alice meets with Josh at her favorite pancake place to tell him she is ready to get back into a relationship. However, Josh says he is seeing someone else, upsetting Alice.
Meg has decided to do IVF to have a baby. Her first donor's sample is unsuccessful, but the second one leads to a pregnancy. Almost soon afterwards, Alice brings Meg to an office party where Meg meets Ken (Jake Lacy). They hook up that night and eventually begin a relationship, but Meg hides the pregnancy from Ken.
Alice takes Robin's advice and starts to put herself back out there. She starts trying new things like bike-riding through the city and taking a cooking class. She attends a Wesleyan alumni networking event and meets a single dad named David (Damon Wayans, Jr.).
Alice and Robin go to a Christmas party held by Josh and his girlfriend Michelle (Sarah Ramos), with Alice having to pretend she is Josh's cousin. Annoyed at having to see the two of them dance together, Alice decides to leave to check out the Rockefeller tree. She bumps into David, who takes her to a building he owns where they get a great look at the tree. They then have their first kiss.
Three months later, Alice and David are dating, but it goes bad when Alice meets David's daughter Phoebe (Zani Jones Mbayise). They start to sing "Can't Take My Eyes Off You", which agitates David because he hasn't gotten over the passing of his wife and he's not ready for someone to step in and be a new mom for Phoebe. He breaks it off with Alice.
Lucy has been seeing a guy named Paul (Colin Jost), which bugs Tom because he realizes he's got feelings for her. After three weeks, Lucy learns that Paul has been seeing other people, and he breaks it off with her at Grand Central Station. Later, as Lucy is reading to children at a book store, she starts to freak out and make a scene in front of all the kids and their parents, going as far as trying to rip off her Spanx with safety scissors. She is stopped by George (Jason Mantzoukas), a man that works at the book store with whom she instantly shares an attraction.
Ken is walking down the street and is shocked when he finds Meg in a store looking for baby products. He finally sees her baby bump and learns she is pregnant. He makes the mistake of calling her crazy (you NEVER call a pregnant woman crazy), and although Ken wants to help her raise the baby, but Meg thinks it won't work, so she breaks it off with him.
Alice runs into Josh and his parents outside the pancake shop. They take a picture, and it appears that Josh's mom still misses Alice. Josh later texts Alice admitting that he misses her too. She then gets an invite from Tom to get drunk. The two of them express their frustrations over the people they've been seeing. Alice then realizes they've reached their drink limit (because according to Robin, in every male-female friendship, there's a number of drinks to pass until they consider sleeping with each other), and she and Tom have sex.
Alice later has a birthday party on a roof. To her horror, Tom, Josh, AND David are all there, having been invited by Robin. Alice tries to avoid all of them and argues with Robin, leading to Robin saying that Alice always falls into a guy's "dicksand" and loses her identity in a relationship. Meanwhile, Tom finds Lucy and tries to admit his feelings to Lucy, but she's engaged to George. She says that Tom doesn't really love her, and that he should move on.
Alice goes to the fire escape to be alone, only to be met by Josh. They go back to make out, until he slips that he's engaged to Michelle. Alice realizes what Robin was talking about, and she leaves. She gets into a cab, which Robin jumps in front of to get a ride for Meg, who is going into labor. The three head to the hospital, but Robin leaves the sisters to their business. Meg gives birth to a healthy baby girl. Ken shows up, having been called by Alice. He tells Meg he loves her, and she admits she loves him too. They rekindle their relationship and spend time with the baby.
Alice goes to Robin's apartment to apologize, and they express their love for each other. Alice then discovers that Robin is very wealthy and has a huge apartment.
In the epilogue, we see what happens to the main characters. Robin is still happily single. Meg and Ken are raising the child together. Lucy and George get married. Tom fixes the plumbing in his home, indicating he is ready to commit in some way. David opens up to his daughter about losing her mother, and they watch a video of Phoebe when she was little with her mother, who sings "Can't Take My Eyes Off You" to her, making David tear up. Alice decides to finally enjoy single life and goes hiking through the Grand Canyon.