As the glow of newlywed bliss envelops Ava and Charlie, they find themselves immersed in the intricate tapestry of Ava's parents' long-lasting marriage, representing 30 years together. Inspired by this enduring commitment, Ava takes it upon herself to orchestrate a surprise anniversary celebration, aiming to rekindle the passion that once bound her parents. However, the atmosphere shifts dramatically when Betty uncovers a shocking secret—her husband Bradley has harbored a decades-old betrayal. In the wake of this discovery, she resolutely decides to separate from him, compelling Ava to welcome her father into their home, all without consulting Charlie.
As Ava grapples with her parents' tumultuous situation, her fixation on mending their fractured relationship begins to put a strain on her own marriage. The once-harmonious newlyweds start to drift apart, their intimacy fading as Ava's all-consuming desire for reconciliation takes precedence over her union with Charlie. Complications abound when Charlie's old friend Gerber arrives with his new Polish wife, Kasia, which forces Ava to confront a hidden truth about Charlie—his past includes a previously unmentioned marriage.
With tensions escalating, Ava and Charlie face another hurdle when her parents' therapist proposes an unorthodox trust-building exercise: rock climbing. In this physically taxing endeavor, one partner scales the wall while the other provides critical support from below. Yet, chaos ensues as Ava's parents engage in a heated argument mid-climb, leaving Betty suspended and pleading for assistance. Distracted by her mother’s distress, Ava abandons Charlie, leaving him to grapple with the situation alone. The fallout is severe: Charlie sustains a serious back and neck injury, emphasizing the significant toll Ava's divided attention has taken on their relationship.
Undeterred, Ava continues to secretly plot the anniversary party in hopes of bringing her parents back together, but her plans are derailed when Betty announces an impending six-month adventure in Asia. With limited time, Ava turns to Charlie for assistance in organizing a night out for her father to foster camaraderie. The evening spirals unexpectedly when they meet Gerber at a bar and are led to a strip club, resulting in a drunken escapade. Upon their return, they stumble upon Ava in a heated discussion with her mother and Bradley, who reveals his intention to marry a young European woman—an idea sparked by Gerber. This revelation triggers a cascade of emotions, with Charlie expressing dissatisfaction about their intimate life and Ava admonishing him for disrupting her efforts.
Meanwhile, Ava's troubles escalate as she and Shelby take Betty speed dating, while Bradley languidly succumbs to sleep at home after consuming tranquilizers. In a moment of clarity, Ava removes the rest of the pills from the house and frantically calls 9-1-1, fabricating a crisis seemingly indicative of a desperate act. Betty ultimately realizes that no one could ever replace Bradley in her heart, even as she learns of his hospitalization.
Later, Charlie confronts Ava regarding the alleged number of pills Bradley had taken, only to discover her manipulative scheme was meant to reconcile her parents. His frustration reaches a boiling point; he lashes out at her for her actions and storms out of the hospital, abandoning their shared life. When Ava visits Charlie at his workplace the next day, hoping to mend their rift, he declines her attempts, expressing a profound aversion to any notion of celebration. Ava's irritation heightens when she accuses him of having an affair with his secretary, Adriana, prompting Charlie to question her motives for their marriage.
The next day brings further turmoil as Gerber asks Charlie to leave, with Kasia's family arriving unexpectedly. As Charlie listens to Gerber converse in Polish, he seeks understanding of the cultural significance of the exchange. Gerber's response serves as a poignant reminder: “If you truly love someone and wish to live a life filled with marital harmony, you must be willing to accept and respect their family, as well.”
Determined to reconcile, Charlie sets off to find Ava at her parents' 30th anniversary celebration. Realizing her hand in their marital discord, Ava seeks his forgiveness. Charlie, moved, renews his vows as Ava fervently responds with a heartfelt "I do." Rather than simply celebrating their rekindled commitment, Charlie suggests they return to the party. However, Ava proposes a more intimate celebration, one that will truly deepen their bond rather than merely mark the occasion.
