The rumor that everyone in his class is having sex, except him, the awkward teenager Otis (so Butterfield) struggles with masturbation. It does not help that his mother, the psychotherapist Dr. Jean Milburn (Gillian Anderson), always meddling in his personal life. Things take a strange turn when the class bully finds out about Jean and asks Otis for help with his sex life with girlfriend Aimee (Aimee Lou Woods). The situation gets even weirder when bad girl Maeve (Emma Mackey) and Otis’s best friend Eric (Ncuti Gatwa) convince Otis to open a sex therapy school in the school, while Maeve and Otis share the profits.