Chance Amber Benson is a twenty-something slacker living in Los Angeles, who relies on a trust fund for finances and shares an apartment with her friend Simon James Marsters, an unsuccessful telemarketer who is self-conscious about his body odor. One day, Simon comes home from the grocery store to find a dead woman in Chance's bed.
The film then goes back several months. Rory Rayder Woods, a struggling soap opera actor with whom Chance had a one-night stand, appears at her door and grows emotional, trying to convince her that they have a connection beyond just sex. To ease the tension, Chance and Simon spin a story about meeting in a mental institution, a tale that unnerves Rory enough to make him stop crying and leave.
Back at home, Desiree Christine Estabrook — Chance's mother — calls to say she’s coming for a visit. To dodge time with her mother, Chance has Simon switch roles with her for the weekend, and Simon spends time with Desiree pretending to be Chance until Desiree tells Simon that she needs to talk to Chance about something in particular. Desiree then reveals that she is leaving Chance's father Malcolm, who is in a relationship with another woman named Heidi. Upset, Chance shares the news with Simon about her parents' divorce and reveals that Desiree wants to stay with them for a while. Simon, in an attempt to comfort her, begs again for $200 to pay off parking tickets. Though hesitant because of a painful experience with a past boyfriend, Chance agrees to lend him the money for playing along with the ruse for her mother.
Feeling uneasy about the idea of her mother living with them, Chance arranges for Desiree and herself to have dinner with Malcolm and Heidi. She also invites Rory, and, as she had hoped, Heidi is immediately smitten with him, drawn in by the soap opera he stars in. During the dinner, Rory manages to pull Heidi away, and Chance questions her parents about the divorce. Malcolm reveals that Desiree had suggested they experiment sexually with Heidi, and Desiree felt rejected when Heidi preferred Malcolm. Desiree insists that he seduced her, but Malcolm denies it, adding that while attractions may come and go, he loves her.
One night, Chance goes out to a nightclub and meets Sara Tressa DiFiglia, who makes advances on her. They bring Sara back to Chance's apartment, where they spend the day in bed. Afterward, Sara suggests they take some drugs. Chance declines and removes the drugs. The next morning, Chance leaves her apartment, only to return and find Simon in her bedroom with Sara, who has apparently overdosed; Chance fears that Sara may have died. In a moment of emotional vulnerability, Simon kisses her, and they have sex. They quickly begin to argue over what the sex means, and Simon leaves.
The next morning, Sara is alive and sits at the kitchen table, thanking Chance for giving her a place to sleep and recover. Meanwhile, Simon runs into Jack Andy Hallett, who recognizes him from the nightclub. Realizing Jack is flirting, Simon tells him that Chance has a crush on him and believes he is straight. Jack explains that, although he is gay, he sometimes has sex with women because he needs human contact, and Simon realizes he also needs that human connection.
Simon returns to Chance's apartment, where she greets him with a warm hug. They apologize for their actions and acknowledge that they are ready to try a relationship.
