Sarah Jo, a naive 26-year-old woman living in Los Angeles, finds herself navigating complicated feelings about love, intimacy, and self-acceptance. She works as a babysitter for Jon Bernthal, who plays Josh, and his pregnant wife Heather. Heather is about to give birth to their son Zach, who has Down syndrome. Sarah Jo lives with her single mother, Marilyn, and her adopted sister, Treina.
Her mother Marilyn, played by Jennifer Jason Leigh, has had numerous husbands and fleeting romances, which influences her somewhat cynical outlook on love and men. Marilyn often gives her daughters advice about seeking validation from men, telling them to directly ask if they find them beautiful. This advice becomes a pivotal moment when, alone in the laundry room with Josh, Sarah Jo bravely asks him if he thinks she is beautiful. Josh, visibly flustered, responds awkwardly, and Sarah Jo, revealing a scar above her vagina from a radical hysterectomy she underwent at 15, confesses that she is a virgin. She explains that her surgery caused her to experience menopause at a very young age, which contributes to her feelings of insecurity.
A tender and somewhat awkward moment ensues when Josh asks if he can kiss her. They share a kiss, and Josh performs oral sex on Sarah Jo, ultimately taking her virginity. His quick ejaculation leaves him embarrassed, but Sarah Jo reassures him, showing her understanding and acceptance. The situation intensifies when Josh, after some hesitation, asks if he can kiss her again, and they end up having sex in the attic, which becomes a recurring intimacy between them.
Following this, Josh takes Sarah Jo on a weekend getaway to a countryside cabin, where they lie regarding their reasons for being away — Josh claiming to be committed to a friend, and Sarah Jo citing a family emergency. During this escape, they indulge in hallucinogenic mushrooms and marijuana, leading to a series of passionate and uninhibited sexual encounters. They also watch pornography together, and Josh gives Sarah Jo a necklace as a token of their bond. As she continues exploring her sexuality through pornography at home, she becomes captivated by a performer named Vance Leroy, admiring his confidence and how he encourages his co-stars.
The plot thickens when Heather's labor begins unexpectedly, and Sarah Jo calls Josh in a moment of concern. Heather notices Sarah Jo's necklace, and soon after, Heather's water breaks. Josh, overwhelmed by guilt as Heather rushes to the hospital, confesses that his feelings for Sarah Jo are complicated and that he has cheated multiple times, even attempting to run away with another woman. In a moment of heartbreak, he tells Sarah Jo to leave, and she is left devastated.
Feeling rejected, Sarah Jo writes a heartfelt letter to Vance Leroy, mentioning that they both bear scars — physical and emotional — and exposing her insecurities about her limited sexual skills, which she believes make her unworthy of love. She also creates an explicit, alphabetical checklist of sexual acts she wants to try, ranging from "anal" and "blowjob" to more extreme things like "necrophilia," which she intends to explore or avoid. Determined to experience pleasure on her own terms, she begins engaging in casual sexual encounters and continues writing to Vance about her escapades. One of her partners, Arvin, a porn assistant, promises to deliver her letter to Vance.
Later, when Josh and Heather are out with their children, Sarah Jo appears unexpectedly in their driveway, sharing with Josh the detailed list of her sexual experiments, which overwhelms and ultimately surprises her. She then runs off, feeling both empowered and vulnerable. Meanwhile, Vance Leroy responds to her letter with a supportive video message, encouraging her to prioritize her own pleasure rather than trying to meet others’ expectations.
Sarah Jo then takes a job caring for a girl with cerebral palsy, finding a sense of purpose and stability. One evening, she invites Arvin over, and they end up having sex, marking a new chapter of exploring her desires freely. Her journey is one of self-discovery, dealing with heartbreak, and learning to embrace her own sexuality, all set against the backdrop of complex relationships and personal struggles.
