In his book The Art of Loving, the renowned psychologist Dr. Erich Fromm wrote about what he termed "the Don Juan syndrome." By this Dr. Fromm meant the person who has a sexual relationship with a person for an erotic release. However, with this syndrome, afterwards there is always a letdown and the person seeks again the heightened eroticism to satisfy feelings of dissatisfaction and desire for something emotionally meaningful. Yet, each time the person engages in the act simply for prurient reasons and for release, he or she is left empty. In the dystopia of Brave New World, the encounter between Lenina and John is no mere solitary episode, but rather a pivotal incident that underscores an intrinsic theme of Aldous Huxley's about the loss of humanity in the inhabitants of the New World.
When the sexual act becomes an outlet for one's anxiety or disastifaction or one's ability to recognize that an infatuation may mature into love, that act becomes empty as Dr. Fromm points out in his book. Lenina, as representative of a world in which true human emotions are conditioned out of people, has lost her true humanity. For, she does not understand the meaning of her feelings for John--while that true human emotion tries to burgeon in her heart. Instead, because of her dehumanization, she interprets her feelings as need of simple release.
Of course, John is repulsed by what he views as promiscuous behavior. He calls her the "strumpet" that she would be in a Shakespearean world, or even the Malpais society. For, John's education in romance has set boundaries for people based upon human respect and dignity. He reacts violently to Lenina because he subconsciously recalls the women of Malapais and their reactions to Linda after she took men as her lovers. He mutters lines from Shakespeare about unfaithful women, with the "drums and rhythm" of the fierce poetry encouraging his action. Underscoring Huxley's theme of the loss of humanity in the New World, this outburst anticipates his later passions after leaving London, especially his violent act of "atonement."
In Chapter 13, Lenina goes to John's apartment because she wants to get him to finally sleep with her. He totally rejects her and actually gets really angry at her. What this shows us is that John believes in what we would call traditional values and that Lenina believes in the sexual values of the brave new world.
In John's value system, women should not be sexually aggressive. Men should have to woo women with words and with deeds (like bringing them a mountain lion's skin as people did in the Reservation). He really wants Lenina, but he wants to win her the "right" way. He wants her to be his ideal woman.
To Lenina, this is all stupid. She has been brought up with the new civilization's values where people just sleep with each other because they want to. She is totally shocked by John's anger.
This whole episode shows quite clearly that John has a much more traditional set of values than Lenina does.