Alyssa Jones (Joey Lauren Adams) is a comic-book artist whose knowing half-smile and Betty Boop squeak slip a hint of innuendo into nearly everything she says. She catches the eye of sensitive Holden (Ben Affleck), a fellow artist who meets her at a comic-book convention he's attending with his partner, Banky (Jason Lee). From their first nimble exchange, Holden and Alyssa appear a perfect match. He writes comics. She writes comics. He's from New Jersey. She's from New Jersey. He likes girls. She likes . . . girls.

Love doesn't get much thornier than this. But Smith doesn't cower from the challenges of a boy-meets-lesbian romance; his reward, and ours, is a temptress who's smart, confident, and brazenly libidinous. In other words, she's no Ellen. Alyssa flirts with abandon, fucks without guilt, and fists on special occasions. Best of all, she's not the type who has to hike up her self-esteem along with her panties the next morning.

Not that Alyssa is a mere primer on lesbian lovemaking -- it's just that, like a junior-high boy with a crush, Smith shows off a bit before exposing his emotional side. Early on, he clings to familiar comedic territory, loading the script with a barrage of self-indulgent Gen X chitchat. In one raucous scene, Alyssa and Banky swap cunnilingual misadventures, going so far as to compare "permanent injuries" suffered during the sport. Smith also pits, with mixed success, the irascible, homophobic Banky against Hooper (an overweening Dwight Ewell), a gay African-American comic-book artist who flicks his limp wrist into a fist of black rage whenever a fan's around.

But just as the wearying repartee hurtles out of control, Smith has Alyssa and Holden melt into a seemingly preposterous, hopelessly passionate affair. The couple's soul-baring dialogue spills out like the real thing: breathless, questioning, heartfelt. Alyssa confronts an insecure Holden about her eyebrow-raising past, recalling that girl in everyone's high school who seemed to like sex just a little too much. But rather than slap a label on her, the film explores her state of limbo. A member of her predictable sapphic crowd scoffs, "Another one bites the dust." Meanwhile Banky eyes her with brooding skepticism, as he struggles with losing his best friend to love. In portraying Alyssa as a busy girl carnally, Chasing Amy also rips at the hypocrisy endured by women whose erotic histories blow away even the most swaggering studs'. Smith layers these provocative themes deftly; only at the end does he stumble a little, tacking on a pat conclusion.

The film plucks winning performances from Adams and fellow Mallrats cast members Affleck and Lee (all play different characters here). Back for the third time are Jason Mewes and Smith himself as the uproarious metalheads Jay and Silent Bob. Apart from the familiar troupe, there's a sly smattering of in-jokes to fuse the director's three-film ode to his home state.

In short, Smith has survived the sophomore jinx that thwarted Mallrats. Nervy, sincere, and irreverent, this unusual romance distinguishes itself from the current crop of upstarts with a knack for finger-snapping banter but little else. It takes guts to make a personal film, and Smith's tender characterization of Alyssa proves he's got the goods. Never mind the convenience store or the mall: this time he dares to set his New Jersey story in the heart.