David (George Clooney) and Georgia (Julia Roberts) Cotton are a once-married couple whose deep-seated resentment for each other stems from their tumultuous relationship that ended two decades ago. Flashing back to their college days, David's desire to remain in Chicago clashed with Georgia's exciting opportunity at an art gallery in Los Angeles, leading to an ill-fated proposal from David on graduation day. Each recalls this pivotal moment with starkly contrasting views; while David perceives it as a romantic gesture, Georgia only feels humiliation.
Their life took another twist when they welcomed their daughter, Lily (Kaitlyn Dever), just a month after their wedding. However, after five challenging years, the couple separated. Now, as Lily graduates from law school, she plans an adventurous getaway to Bali with her friend Wren (Billie Lourd). Adding complications to the mix, Georgia is involved with a much younger French man, while David struggles with the idea of his daughter falling into a potentially age-inappropriate romance.
While exploring the beautiful underwater world on their vacation, their boating tour leaves them stranded, and they are saved by Gede (Maxime Bouttier), a young Balinese seaweed farmer. The connection between Gede and Lily ignites sparks, as he introduces her to the serenity and fulfillment of his nature-driven lifestyle on the island. Although they barely know one another, Lily makes a bold decision to marry Gede and stay in Bali indefinitely, foregoing her promising legal career.
Realizing that both David and Georgia fear their daughter is making a hasty choice reminiscent of their own past mistakes, they momentarily put aside their animosity to join forces. On their flight to Bali, they are surprised to find that Paul (Lucas Bravo), Georgia's boyfriend, is the pilot. He wishes to surprise Georgia by visiting Bali shortly after their arrival.
As tensions rise, the divorced couple pretends to accept the relationship while secretly plotting to derail the wedding. Their antics escalate, including the mischief of attempting to steal the wedding rings, which Gede's family quickly mitigates. Faced with overwhelming family unity, love, and acceptance from Gede's parents, David and Georgia grapple with their discomfort in blending with him and his large family.
David, who cautions Gede that Lily may soon outgrow this life, is confronted by Wren's insistence that Lily’s happiness is genuine. Amid heartfelt conversations, David reflects on their own failed marriage, comparing it to his idyllic dreams of togetherness which vanished into debt and adult responsibilities. In an amusing turn of events, David and Georgia find themselves drunkenly engaged in beer pong with Gede and Lily, temporarily rekindling the fun of their younger years.
Compounding the chaos, Paul surprises Georgia with several marriage proposals, only for the moments to veer into unintended comedic disasters. Gede starts to connect the dots, suspecting David’s motivations, but keeps his feelings hidden from Lily. When confrontations arise surrounding the stolen rings, Lily demands either support or the choice to leave, prompting Georgia to empathize with her daughter’s fears of repeating history.
Ultimately, the couple realizes they must embrace their daughter's choices if they wish to remain in her life. As Gede requests a sincere blessing before the wedding ceremony, David finds the courage to affirm not only their support but the valuable lessons learned through their failures. As they participate in the Balinese marriage customs, it's clear they both are shaped by their past but also willing to appreciate the love their daughter has found.
The morning after the wedding, Georgia finds herself unable to commit to Paul and acknowledges her feelings for her ex-husband, leading to a bittersweet farewell with their daughter. Just as contemplation sets in about their future, David and Georgia decide to seize the moment, plunging back into the waters of their youth and the vibrant possibilities of life together once more.
