Don and Ellie Griffin are a long-divorced couple who have remained cordial for the sake of their children. However, their family is thrown into a whirlwind of preparation and anxiety when they are forced to pretend to be happily married once again for the upcoming wedding of their adopted son, Alejandro. The charade is necessary because Alejandro's devoutly Catholic biological mother is unexpectedly flying in from Colombia for the wedding, and she is unaware of Don and Ellie's divorce. Fearful of her reaction due to her religious beliefs, Alejandro asks his now-separated parents to put on the façade of a loving, intact family to avoid scandal and discomfort during her visit.

As the big day approaches, the Griffin family is engulfed in a series of comedic and emotionally charged situations. The Griffin's other two children face their own personal challenges and secrets that start coming out amidst the wedding chaos. Their daughter, a lawyer coming off a breakup, questions her life choices, while their other son grapples with the pressure to please his parents and the reappearance of an old flame. The situation is further complicated by Bebe, Don's long-time girlfriend, and Ellie's former best friend, who is also involved in the wedding. Tensions rise as old wounds are opened, past relationships are examined, and the Griffins must navigate the pretense of domestic bliss while confronting their own complicated history.