In the sixth episode of the final season of "My Brilliant Friend," titled "The Cheat," the narrative delves deeper into the complexities of Elena's (Lenù) relationship with Nino Sarratore, exposing the cracks in their union and the repercussions of Nino's infidelity. The episode masterfully captures the emotional turmoil that Lenù experiences, as she grapples with the reality of Nino's unfaithfulness, which is nothing new to his character but devastating to Lenù nonetheless.

The episode opens with Lenù's increasing suspicions about Nino's loyalty, which are exacerbated by the demands of her own life. She is torn between her responsibilities at the clinic with her ailing mother, Immacolata, and her duties at home. Immacolata's condition worsens, leading to heart-wrenching scenes where she makes demands of her sons and Marcello, showcasing her fierce determination to control the fate of her family even in her final days. Lenù and Immacolata's relationship reaches a surprising warmth before Immacolata's peaceful death, offering a glimmer of hope amidst the sorrow.
As Lenù navigates her mother's passing, she is also confronted with the challenges of motherhood and her own marriage. The arrival of her daughter Imma and Lila's daughter Tina adds a new layer to the narrative, as Lenù and Lila's paths continue to run parallel, each dealing with the trials of childbirth and motherhood in their own ways. Lila's labor is depicted as a fierce battle, contrasting with Lenù's more natural approach to creating life.
The episode also explores the dynamics of Lenù's social life, as she and Nino host a dinner party for one of Lenù's editors. Nino's aggressive pitching of his work and his blatant disregard for Lenù's own writing schedule highlight his self-centered nature, further distancing Lenù from her once idealized image of him.
The turning point of the episode comes when Lenù discovers Nino's affair with their housekeeper, Silvana. This revelation is a stark contrast to the quiet, eerie calm of the apartment, and Lenù's immediate departure with her daughter Imma is a powerful moment of realization and heartbreak. The episode effectively uses flashbacks to Lenù's past, reminding viewers of the history that has led to this moment, and the profound impact of Nino's betrayal.
Lenù's refuge at Lila's home provides the setting for the episode's climax. Lila, despite her own reservations, reveals Nino's relentless pursuit of her, both before and after his relationship with Lenù. This confirmation of Lenù's worst fears shatters her world, as she is forced to confront the truth about Nino's character and the facade of their relationship.
"The Cheat" is a powerful exploration of betrayal, desire, and the struggle for self-identity. It highlights the ripple effects of uncontrolled emotions and the lasting impact of formative desires on the characters' lives. The episode is a testament to the series' ability to delve into the intricacies of human relationships, capturing the raw emotions and the harsh realities that define the lives of Elena and Lila.