Is lesbianism a passing phase in ''Kissing''?

If you attended college anytime after the 1970s, you may be familiar with the phenomenon of the four-year lesbian. To wit, that woman who came noisily out of the closet during her freshman year, maintained her gayness throughout her time on campus, yet magically reverted to the straight kingdom somewhere between graduation and the time you ran into her, her three kids, and her minivan last week at the supermarket.

If that woman was a movie, she would be ”Kissing Jessica Stein.”

Which is a shame, really, because the film is terrifically engaging while it’s up there on the screen: a lightweight, low-budget comedy of eros that dives headfirst into the swimming pool of gender fluidity. It’s only when the lights come up that you realize no one got very wet.

As played by writer-actress Jennifer Westfeldt, Jessica Stein’s a recognizable type: the lonely urban single woman, funny and smart and burnt-out from looking for a guy who’s funny and smart. (The setting is familiar, too. Those caressing longshots of midtown Manhattan, the classic jazz on the soundtrack, the heroine dithering herself into a neurotic blur: We’re in Woody Allen country.) Coming across a personal ad that drops her favorite Rilke quote, painter/copy editor Jessica is at first disappointed to note that it’s in the ”Women Seeking Women” section. And then, not sure why, she decides to call.

The woman on the other end of the line is Helen (Heather Juergensen, who cowrote the script with Westfeldt, based on their 1997 off-Broadway play), an art gallery manager with a wild streak — she juggles three boyfriends — and an approach to gender that could be summed up as ”Why not?” They meet in a bar. Jessica bolts. Helen calmly reels her back in. A spark is struck.

But is that spark mere friendship or true romance? Something in between, and the uncertainty is both refreshing and a bit of a cheat. As the two women slowly work their way toward physical intimacy, ”Kissing” plays Jessica’s manic, hyperarticulate indecisiveness as the stuff of comedy, and it is, for two or three scenes. After that, she’s just a pill, with both Helen and the audience sharing in the frustration. The ultimate gag, of course, is that Jessica’s friends and family are far more open to her being gay than she herself is. Tovah Feldshuh, in particular, has a honey of a front-porch monologue as Jessica’s know-it-all mom, torn between shame, loss, and her daughter’s sudden chic.

Eventually, we are given to understand that Jessica and Helen have consummated their relationship, safely off-screen and with little ensuing handholding. How can we tell? Because Jessica starts wearing make-up and short skirts: Lesbian love is, apparently, the best makeover a gal can have. Still — MAJOR SPOILERS FROM HERE ON — we know it can’t last, because hanging around the edges is Josh (Scott Cohen of ”Gilmore Girls”), Jessica’s ex-boyfriend, current boss, blocked writer, and a Jewish Boy of such appealingly cranky Niceness that you know the movie and Jessica can’t resist him. And they don’t.

And so it turns out that Jessica isn’t interested in exploring her gay side after all. Her genuine attraction to Helen is subsumed into something pre-sexual; theirs is the sleepover that never ends. But is anything wrong with that? Especially when it all ends with rueful, happy-and-wiser cheer?

Well, yes, and it’s this: Jessica’s problem isn’t that she has difficulty being gay, as the movie implies. As Westfeldt plays her, neurons rattling with thoughts and thoughts and THOUGHTS, Jessica has difficulty being sexual, period. Like the film itself, she’s all brain and no body, and sending her off to a bright future with the boychick is a lie: She’ll be miserable no matter who she’s with. It’s a classic bait-and-switch, and here it comes off as unintentionally retrograde. ”Kissing Jessica Stein” wants us to believe that Jessica has graduated from lesbianism a better person. All she has done, really, is pick an exotic major.

Do you think ”Kissing Jessica Stein plays it straight or not?