Cédric Roberge, a 42-year-old engineer, and his wife Nadine Nadine are a suburban couple who have just welcomed their first child, a daughter named Léa. One night, while at an MMA event with friends, Cédric gets drunk and kisses Chantal Tremblay on the side of the head during a live television broadcast. The moment goes viral overnight, and he is indefinitely suspended from his job. Nadine, who is grappling with postpartum depression, decides to end her maternity leave and return to work, leaving Cédric to take care of Léa. Instead, Nadine secretly checks into a local motel for some alone time.
Cédric's brother Jean-Michel, a journalist who wrote a scathing op-ed on the incident, confronts him about his misogynistic tendencies. Nadine suggests that Cédric write a letter of apology to Chantal. Meanwhile, Cédric hires a cheery and mysterious babysitter, Amy. Later that day, Nadine arrives home while Cédric is out and is surprised to meet Amy. That night, Cédric is aghast when Nadine admits that she has been pretending to go to work while hiding out in a motel. Assisted by Jean-Michel, Cédric seeks to redeem himself by writing Sexist Story, a book featuring 200 letters of apology to women everywhere, including Chantal as well as Beyoncé and Kim Kardashian.
One day, Cédric and Nadine are stunned when Amy arrives at their house in a sexy French maid uniform, claiming that wearing a uniform motivates her. While alone with Amy in her bedroom, Nadine begins to suffer a panic attack, and Amy calms her down. Later, Nadine wears a lavender cape that was gifted to her by Amy around the house, leaving Cédric and Jean-Michel puzzled. Amy, still dressed as a French maid, also gifts Nadine a servant bell and acts as her personal servant.
Cédric and Jean-Michel sign with a publishing executive who views Sexist Story as a potential bestseller. However, when Cédric's friend Tessier Tessier recognizes Amy from a LARP event they attended for a mutual friend's birthday where she was dressed as a "medieval hooker", Jean-Michel pushes Cédric out and resolves to write the book himself. After Jean-Michel's book launch, Cédric and Nadine go to the nearby woods to have sex, whereupon she attempts to peg him with a strap-on dildo (another gift from Amy), prompting Cédric to flee in horror.
Returning home that night, Nadine breaks down in tears and is consoled by Amy; it is implied that the two women have sex. Afterwards, when asked by Amy, Nadine informs her that she no longer needs her. As Cédric returns home the next morning, he sees Amy leaving the house and disappearing into the fog. Cédric then joins Nadine in bed, and they hold hands. Some time later, Jean-Michel appears on a talk show to promote Sexist Story and becomes emotional when reading an excerpt from the book dedicated to Amy. Nadine throws away Amy's gifts, but the strap-on dildo is thrown back at her as the garbage truck drives off.