In the introduction to this story collection first printed on the Web site nerve.com, Murnighan offers a simple definition of sex: "One body bumping against another." Out of this simplicity, he and co-editor Field compile a rarity: a sexy book about sex. There are a number of ways to enjoy these 40 short piecessociological, psychological, physiological, and in its best entries, all three intertwine. Rachel Sherman's"Over Chinese" features a father who will, Ilise Benun's"Complex Electra" features a father who won't. In Dani Shapiro's"Bed of Leaves," the older man is 28. In Susan Neville's"Terrarium," he's 40-something. Stacey Richter's"When to Use" explores what douching can and cannot do. Dennis Cooper's epistolary"The Finish Line" shows what letters can and cannot do. None of the stories flinches from sexthe actual bumping together of bodies. But the physiology is always located in a psychosociological continuum. In Elizabeth Wurtzel's"Alex," the pleasurably painful intercourse a rock-music critic enjoys with a well-endowed, aspiring heavy-metal star, leads to something of an epiphany:"It's not because it feels good. It's just because it feels at all." In Karen Bender's"Robbery," an elderly couple reclaim their house through a protracted, room-to-room act of lovemaking, after permanently relocating their retarded daughter. Henry Wren's"Intimacy" concerns a Washington, D.C., limo driver who videotapes young couples having sex in the back seat on their prom nights while he circles the Iwo Jimawarmemorial, inscribed, we learn, with his dead older brother's name. Some of the stories misfire: Jerry Stahl's"Perv" is one-dimensional; Mary Gaitskill ambitious, essayistic"Folk Song, 1999" is stillborn. Meanwhile, many little-known voices grace this collection. There are also some big names: Jay McInerny, Robert Olen Butler, A.M. Homes. Sex books are often avoided, and for good reason. To avoid the porn charge, they get too cerebral; to attract a sizable audience, they get too one-dimensional. Full Frontal Fiction avoids those errors. Like a good date, it's both smart and sexy.