After a day of filming her cable drama, The Delaneys, Allie turns down an invitation from her costar Trevor to go out. She’s flying to Boston for the wedding of her college friends. At the studio, she reflects on the show ending after its final season, her gratitude for the opportunities it has given her, and her friendship with the cast. She thinks about her relationship with Dean, his work as a teacher and hockey coach, and the privileges that come with dating him. A car service takes her to a private airport to board the jet owned by Dean’s wealthy parents. During the drive, she texts her best friend, Hannah, who’s already in Boston. She then texts Dean, who responds with a flirtatious message about his anticipation of her arrival.

Allie arrives at Garrett and Hannah’s Boston home, where she and Dean are staying for the weekend. The four friends catch up before Dean, eager to be alone with Allie, takes her to their guest room. They have sex in the shower. Afterward, as Dean prepares for Tucker’s bachelor party, they discuss the weekend’s plans. Allie mentions that Sabrina’s bachelorette will be a low-key tea party that includes Tucker and Sabrina’s three-year-old daughter, Jamie. When the topic of children comes up, Dean repeats Tucker’s sentiment that they should all start families, but Allie dismisses the idea, stating that kids are the last thing on her mind. Dean looks forward to proposing to her as soon as they return to New York, while reminding himself that the wedding weekend should remain focused on Tucker and Sabrina.

On the way to Tucker’s bachelor party, Garrett has already told Tucker about Dean’s plan to propose at the wedding, and Tucker raises it with Dean in the limo. Although Tucker initially pretends to support the idea, he soon launches into a long, menacing, and darkly comic threat, promising to ruin every significant moment of Dean’s life if he upstages the wedding. Dean gets the point and drops the idea. The friends arrive at TD Garden, where the bachelor-party surprise is revealed: Thirty of their former Briar University hockey teammates are waiting in the locker room. Tucker is overwhelmed with joy. The group is set to play a private hockey game on the Boston Bruins’ home ice, a bachelor-party gift that Dean helped organize by arranging and funding the reunion of their former teammates while Garrett and Logan helped secure the rink.

Allie attends Sabrina’s bachelorette party, a tea party at the Taj hotel. The guests include Hannah; Grace; Dean’s sister, Summer; and Sabrina and Tucker’s daughter, Jamie, who delights everyone. During a conversation about marriage, Summer complains that her boyfriend hasn’t proposed. Allie explains that although she considers Dean her “forever person,” she isn’t ready to get engaged or married, viewing engagement, marriage, and children as a sequence of steps she isn’t prepared to take. Sabrina, whose own pregnancy was unplanned, validates Allie’s right to wait without pressure, while also speaking positively about her own situation with Tucker. The discussion reinforces Allie’s belief that she wants to postpone starting a family for much later in her life.

At Tucker and Sabrina’s wedding reception, seeing the newlyweds together makes Dean imagine marrying Allie. He quietly tells her that they will get married someday, and she agrees but clarifies that it will be “well into the future” (107). She also teases that he must first get her father’s blessing, which makes Dean nervous. Later, while catching up with his former Briar teammates, Dean reflects on the friendships that have endured since college and briefly remembers their late friend Beau Maxwell. Their former coach, Chad Jensen, gives brief remarks only after being pushed by his girlfriend, Iris, and the group. After Jensen and Iris leave, Dean’s friends get into a speculative conversation about the coach’s sex life. After overhearing the conversation, Iris jokingly remarks, “He definitely fucks” (112), before walking away.

At the reception, Allie worries that Dean may be tempted to propose because of Tucker and Sabrina’s wedding. While looking for Hannah at the reception, Allie overhears Logan calling Grace “Mrs. Logan.” Grace pulls Allie into an empty restroom and confesses that they secretly married over New Year’s but are keeping the marriage secret until after graduation. Their conversation is interrupted by Hannah, who emerges from a stall after being sick. Hannah reveals that her period is three weeks late and that she thinks she might be pregnant. Both Grace and Hannah make Allie swear to keep their secrets, particularly from Dean, Logan, and Garrett. Allie is left feeling overwhelmed by having to keep both revelations to herself until Grace and Hannah are ready to share them.

Back in New York after the wedding weekend, Dean visits Allie’s father, Joe Hayes, in Brooklyn to ask for his blessing to marry Allie. Joe, who lives with multiple sclerosis, immediately guesses Dean’s intentions and gives his blessing before Dean can make his speech. He also approves of the engagement ring and tells Dean that although they’re young, he won’t stand in the way because Allie loves him. Later, Dean goes to his mother’s law office in Manhattan and asks to use the family’s penthouse that night. He shows her the engagement ring, and she’s overjoyed. He makes her promise not to tell his father or Summer until after he has proposed, as he wants to keep the proposal a surprise.

Dean surprises Allie with a romantic dinner at his family’s penthouse. After seeing him dressed for a special occasion, Allie worries that she has forgotten an anniversary, but Dean reassures her. When she realizes that he’s about to propose, she stops him, reminding him of their previous conversations where she stated that she wasn’t ready for that step. Dean argues that he thought she was only asking to postpone marriage and children, not an engagement, but Allie feels like he has ignored her wishes. The discussion escalates into a fight, with Dean feeling hurt and rejected. He abandons the proposal, angrily ends the evening, and storms out, leaving Allie alone.

For two days after the disastrous non-proposal, Dean gives Allie the silent treatment. Frustrated, she accepts an invitation to go to a club with her Delaneys costars, including Trevor, Malcolm, and Seraphina. When Dean finds her dressed to go out, they have another argument, and he reveals that he already asked for her father’s blessing to get married. At the club, Allie discusses the fight with her friends. Seraphina uses a “relationship ladder” analogy, suggesting that Dean needs the commitment of an engagement to feel secure. The advice makes Allie realize that she has been inflexible. She texts Dean and learns that he’s in a hotel in Newark, New Jersey, with his friends. Elijah, a friend of Malcolm’s whose family owns the hotel chain, gives Allie an idea, and she asks him for a favor.

In a Newark hotel room, Dean and Garrett discuss the fight with Allie. Garrett points out that Dean ignored what Allie had clearly communicated, making Dean realize that he should accept that she’s not ready yet and continue their relationship until she is. Their conversation is interrupted by a shriek from the adjoining room, where they find Allie confronting a naked Logan. Allie had used a keycard to surprise Dean but entered the wrong room just as Logan was getting out of the shower. Once the confusion clears, Allie and Dean talk alone. She apologizes for her rigidity and, explaining her change of heart, proposes to him. Dean happily accepts. The next morning, back in their apartment, they receive an engagement gift from Logan and Grace: the haunted porcelain doll, Alexander. When Allie casually refers to Grace as “Mrs. Logan,” she inadvertently reveals to Dean that their friends are secretly married.