It has been 15 years now since the Stonewall riot, the event that triggered the gay liberation movement (and that is commemorated annually at gay pride days across the country). Fundamentalists may still rant and platform-writers cringe, but during that time American society has made its peace with gay men and lesbians to the extent that the era of mass stealthiness seems to be over.

Gays have unmistakably claimed urban districts -- the Castro, Greenwich Village, Dupont Circle -- as their own. Gay activists are giving way to gay politicians. A young artist like David Leavitt can write stories in which homosexuality is neither an exotic effluvium nor an all-consuming issue of identity but a steady jumping-off point for further exploration -- and place them in mainstream publications like The New Yorker.

Leavitt's slant on his subject matter in this collection of stories is familiar: He captures the deep-rooted tensions between adult gays and their families and the efforts of childless gays to carve out families among their peers. In "Territory," a mother who has accepted her son's sexuality in the abstract and at a distance finds herself dismayed when he brings his East Coast lover home to California for a visit. The son, in turn, enjoys flustering her. He and his lover sneak out at night to make love under the stars and refuse to answer her call when she investigates the noise. Before the visit is over, the son feels he has attained a needed "arrogance of mastery. He is glad his mother knows that he is desired, glad it makes her flinch."

In "Dedicated" the makeshift family consists of gay lovers Andrew and Nathan and their straight pal Celia. Considered by her friends to be a "litmus test" -- if she likes a man, he's bound to be gay -- Celia esteems gay men for "their willingness to commit themselves to endless analytical talking . . ."

Having heard Andrew and Nathan out -- together and apart -- for years, Celia believes she knows them better than they know themselves: She has acquired an Andrew-and-Nathan expertise that she is reluctant to give up even when they slight her. She knows why, for instance, though the lovers regularly needle each other to psychic rawness, Andrew regards them as indissolubly linked. "Growing up a fag is a strange thing," he tells her. "You never learn about boys' bodies because you're afraid of what you will feel and you never learn about girls' bodies because you're afraid of what you won't feel. And so the first time you sleep with someone, it's like the first time you've ever noticed a body . . . I remember I was amazed to see the way [Nathan's] diaphragm moved up and down when he slept because I'd never watched anyone sleep before. And for showing me that, because of that, I'll always love him, even if he acts the way he does." She also knows that refereeing their battles helps keep her from confronting the lovelessness of her own life.

The finest passages in Leavitt's fiction reveal those traits and motives that set his homosexual characters apart from the straight world, those moments when being gay seems to entail not just different ways of making love but different approaches to reality. In "Out Here," a story of a family reunion, a lesbian romps across the lawn, tossing her hair and "making wheezing noises." Pulling her lover down to the ground with her, she explains her bizarre behavior. "I haven't done that in ages. When I was a kid I could play horse for hours. I used to like to spin, too. I'd just twirl, like a top. Everyone thought I was nuts. But I liked the way everything blurred and only my own body stayed in focus."

Other stories, in which gay characters are either absent or relegated to minor roles, lack the originality and perspicaciousness of Leavitt's best work. Through several of them trudges a stock long-suffering mother, embittered by a husband who has suddenly ditched her in middle age. Leavitt's solemn presentations add little to our understanding of such women's plights.

But if for the moment Leavitt's range has its limits, the problem is minor. This is his first book, and, still in his early twenties, he is presumably a developing writer. He is also a remarkably gifted one, and his special material has only just been tapped.