Junot Díaz’s fiction alternately unsettles, amuses, challenges, delights, and wounds. His new collection of stories, This Is How You Lose Her, is especially wounding, playing nine variations on the theme of faithless Dominican-American men and the women they betray. Díaz doesn’t moralize—if anything he plays down-and-dirty with the sex lives of his characters. He has always been a provocateur, albeit one who presents himself as a realistic writer simply delivering the news, straight-up, about the Dominican-American scene. But though these narratives may appear at first to spring from the tradition of the minimalist American short story (Hemingway begets Carver begets Díaz), beneath their simple surface boils a rich cultural stew. Every story is informed by a strange, slant sensibility, the mark of a true original.

All but one feature Díaz’s charming and infuriating alter ego, Yunior, who figured prominently in the author’s first collection, Drown, and in his Pulitzer Prize–winning novel, The Brief Wondrous Life of Oscar Wao. Yunior is a smart Dominican boy, confident but self-aware, who comes of age in a snow-covered New Jersey so foreign it might as well be the moon. Amid the grim urban landscape of American poverty he must contend with a brutal, womanizing father who eventually abandons him, and with an older brother bent on outdoing the father both in sexual conquest and in self-destructiveness. Just when he thinks he has loosened the psychological grip of both father and brother by escaping into a life of reading and writing, Yunior discovers that he hasn’t actually escaped at all. It’s an old story made new in This Is How You Lose Her, with a host of literary pleasures and a hard dose of pain.

These stories create the illusion of being spoken extemporaneously, in an English peppered with Dominican slang, yet in reality every sentence is precisely calibrated. Díaz’s fiction is emotionally hot, iced down with cool irony. He can be a little showoffy in acknowledging his literary debts, but gets it right so often you’re inclined to forgive the occasional strutting. Look how he telegraphs a reference to Melville with a wittily apt verb: “A lot of the time she Bartlebys me, says, No, I’d rather not.” Or listen to Yunior, intimidated by professorial Eurotourists on a Dominican beach, but still cocky enough to say they look like “budget Foucaults.” Díaz throws postcolonial theory and Dominican history at his readers because Yunior is postcolonial theory and Dominican history. He’s all over pop culture, too. The language of these stories is coarse and bilingual and sometimes vacuous because our culture is coarse and bilingual and often vacuous. If dirty words make you cringe, if you don’t like consulting the Urban Dictionary to understand characters cursing in Spanish, this is not for you.

If, however, you are interested in struggling lives rendered with precision, intelligence and sympathy—or merely in the glimmers of illumination that good stories mysteriously provide—This Is How You Lose Her offers a powerful cumulative effect. These stories are much more than simple exercises in emotional release. Two of them, “Nilda” and “Otravida, Otravez,” give wonderfully empathetic visions of complex females. Nilda, the awkward, promiscuous girlfriend of Yunior’s brother Rafa, remembers meeting Yunior when she was a tank-top-wearing kid who wanted to play baseball, and reminds him how “you made me put on a shirt before you’d let me be on your team,” revealing a complicated, poignant longing for male protection. Yasmin, the only female narrator, leads her American lover away from his wife, and in the telling defies a reader to condemn her.

In depicting the sexual hurts of a specific subculture, these stories imply a great deal about male faithlessness and the objectification of women in the culture at large. Díaz portrays machismo as an inevitable product of the brutal heritage of Dominican dictatorship, underwritten by the American Way of Life, but he won’t let Yunior hide behind political or psychological justifications for his cheating: “You claim you’re a sex addict and start attending meetings. You blame your mother. You blame your father. You blame the patriarchy. You blame Santo Domingo.... You try it all, but one day she will simply sit up in bed and say, No more....”

Sure enough, the love of Yunior’s life does just that. The final story in the collection, “The Cheater’s Guide to Love,” takes Yunior through five years of mourning her loss, and leaves him undertaking to write a book about how he betrayed and hurt her, “because it feels like hope, like grace—and because you know in your lying cheater’s heart that sometimes a start is all we ever get.” Having listened in on men trash-talking about the women in their lives, having watched them compulsively betraying the people they love, we readers understand that it will take a heap of grace for them to remember who they are, and what love is.