Maddie Barker, 32, is an Uber driver and bartender based in Montauk, New York. Her car has been repossessed and she is in danger of bankruptcy because she is behind on property taxes on her house, which she inherited from her mother. Desperate to protect her home, she accepts an unusual Craigslist entry. Her new employers, two wealthy cryptocurrency investors named Beckers, are asking her to date her 19-year-old son Percy Becker in exchange for her Buick Regal. Percy is shy and has no experience with girls, drinking, partying, or having sex, so her parents want to give Percy her confidence before enrolling at Princeton University in the fall. Maddie tries to seduce Percy at the animal shelter where she volunteers. But after making her offer to drive her home, he mistook her for kidnapping and put her pepper spray on her. Despite this, they agree to a date the next day. The next night, Maddie and Percy meet at a bar and go skinny dipping on the beach. While they are in the water, a group of drunken teens try to steal their clothes. Maddy fights Percy, who frightens her naked, and Percy demands to take her home. When she tried to leave without him, he jumped into her car naked and they fled the police. She and Percy attempt to have sex, but Percy develops a rash from anxiety, which Maddy tends to.

Maddie and Percy continue to see each other, tell more about each other, and develop a friendship. Revealing that they have never been to prom, they both mimic prom night and go to a fancy dinner. Percy meets an old school friend at a restaurant and invites him to a party. After he and Maddie disagree about long-term plans, he goes to a party while Maddie goes looking for him. She discovered him after taking ibuprofen with alcohol. Percy confesses his love to Maddie.

The next day, Percy tells her parents that he wants to stay with Maddie in Montauk. Her panicked father offers to lend her a car if she can convince her to go to Princeton. Percy accidentally overhears Maddy’s deal with her parents. He invites Maddie to dinner with her parents and she reveals she knows about their deal. While Maddie and her parents argue over who told him about the deal, Percy crashes the Buick into a tree, wrecking it. Percy returns and tries to have sex with Maddie. After getting premature ejaculation, a betrayed Percy ends their relationship.

Maddy recovers the wrecked car and strengthens her resolve to pay off her debts. After spending the rest of her summer traveling with Uberling, she managed to save enough money to protect her home and fix her car. Her agitated Maddie tells her friends Jim and Sarah about it, but Sarah asks Maddie if she really wants to stay in Montauk or just for her mother’s sake. The couple also confirmed that they moved from Montauk to Florida due to housing costs. Maddie looks back on her life and tries to correct her mistakes. She reunites with Percy at a Princeton mixer and apologizes for cheating on her. Her unconvinced Percy starts running in her car, just as Maddie jumps on the hood of her car. Percy goes blind and plunges her car into the sea. The two reconcile and promise to remain friends while the car is towed. Maddie decides to sell the house to Jim and Sarah and move to California.