In Closer, the objective of the scene where Anna admits her affair might be to showcase the complexity of her character and to speak to alternate forms of intimacy.
The scene begins with Larry admitting to Anna that he “slept with someone in New York.” He had sex with “a whore.” Anna asks why he didn’t tell her earlier. Larry says, “I couldn’t lie to you.” Anna says, “It’s fine.”
Anna’s reaction and subsequent revelations reinforce her multifaceted nature. The scene counters the common trope of the betrayed woman. Anna is not a simple victim of Larry’s infidelity; she has secrets of her own. Unlike Larry, her affair is meaningful. Thus, the scene creates a sharp twist. She’s not leaving Larry because he had a rather insignificant affair with a sex worker, but because she’s in love with another man.
The scene also spotlights the intricacies of Anna’s methods of communication. Sometimes, she responds to Larry calmly. Other times, she shouts back. Then there are moments when Anna uses nonverbal communication. About midway through the scene, Larry makes the claim that they’re happy. Anna refutes Larry’s assertion with a despondent facial expression.
Near the end of the scene, Anna, pressed by Larry, details the kind of sex they had. Here, it's possible to argue that Larry finds a way to stay close to Anna by compelling her to graphically recount her sexual activities with Dan.