The central plot of "Call Me by Your Name" follows the six-week summer romance between Elio and Oliver, which culminates in three intensely romantic days in Bergamo before Oliver must return to the United States. The departure is heartbreaking for Elio. After he returns home, his father, revealing he has known about the relationship all along, delivers a profoundly moving monologue. He tells Elio that the bond he and Oliver shared was rare and beautiful, and urges him not to bury his feelings but to embrace the pain along with the joy, confessing that he himself has never had such an experience.
The film's final twist arrives several months later, during Hanukkah. Oliver calls the Perlman family and speaks with Elio. During the call, he reveals that he is engaged to be married to a woman he had been dating on and off. The news shatters Elio. He addresses Oliver as "Elio," a final, heartbreaking invocation of their shared intimacy. Oliver, understanding, responds "Oliver," and tells him, "I remember everything," confirming the depth of his feelings before the call ends. The film concludes with a long, unbroken shot of Elio sitting in front of a fireplace, silently crying as he processes the news and the finality of their separation, while his parents unknowingly prepare dinner in the background. This ending solidifies the film's theme that such a perfect, idyllic love could not survive outside the bubble of that one summer, succumbing to the pressures of conventional life.
It's important to note that the film adapts only a portion of André Aciman's novel. The book continues for another twenty years, depicting a few brief, poignant reunions between Elio and Oliver, who is married with children. The film's decision to end on this note of immediate heartbreak gives it a more concentrated, tragic power, leaving Elio's future open-ended.