Only in the past several months have films about alternative lifestyles become more common. But as the genre evolves and grows into its own, it’s not surprising that filmmakers have begun to branch out, viewing the once taboo subject matter from different perspectives. While it’s no “Brokeback Mountain” or “Transamerica,” and likely won’t win any awards, “Imagine Me & You” is surprisingly charming.

That said, if you have always hated romantic comedies, you’ll probably hate this as well.

It’s not so much that the film is strictly bad, just that the only attempt to flesh out an old familiar romantic comedy plot was to change the dashingly handsome hero into a chain smoking florist named Luce, played by Lena Headley.

Tragically, while Luce may cut a striking figure in her collared shirt and vest, she spends her nights caring for her divorced mother rather than cruising for chicks. All that begins to change though, when she meets the lovely Rachel — played by the plausibly British Jersey girl, Piper Perabo, of “Coyote Ugly” fame — when doing the flowers for her wedding.

Obviously, the circumstances of their meeting present several problems for the pair and the girls’ sexual tension is intermingled with guilt — as well as delightfully silly one-liners, including “vagitarian” and “gay as a tennis player.”

To make matters worse, Rachel’s new husband Hector (“Heck”), played by Matthew Goode of “Match Point,” is practically perfect. Handsome but demure, sporting a side part that would do Pee-wee Herman proud, Heck is honorable, sensitive and fairly funny.

In fact, defying the stereotype that all lesbians are surly (or burly) man-haters, the only characters with particularly witty lines, emotional maturity or depth are male. Anthony Head, also known as Giles from “Buffy the Vampire Slayer,” plays Rachel’s father. The aged Ned may be suffering from senile dementia. He may be eccentric or an alcoholic. Or he may just be British — frankly, it’s hard to say. What is clear, though, is that he’s adequately hilarious and that’s enough.

More serious viewers may object that the plot line is ridiculous, implausible and somewhat immature. “Imagine Me and You” simplifies the battle between impulsivity and stability into a brief, if troublesome, inconvenience. Apparently the only way to reconcile an unconventional extramarital love with an otherwise near perfect life is to have the most liberal and understanding husband and father in the entire world — which means that Rachel’s life remains staggeringly close to “near perfect” even after her tumultuous lesbian love affair.

Despite being totally preposterous, plenty of the situational comedy is also imbues the genre with some much needed levity. When Rachel and Heck, in the midst of their own outdoor sexual escapades, encounter two men having sex in the bushes by the side of the road, we begin to see that gay sex can be just as amusingly awkward as straight sex and that we’re allowed to laugh.

And, when the credits rolled, yes: the ending is happy. Arguably too happy. Luce and Rachel are reunited by a meandering bicyclist with a penchant for the Turtles and everyone ends up happy and satisfied in a way that they never envisioned when the movie started. But the film is pleasant and reassuring without trying to be too hip, reminding us that lesbians can be cute and fun and that London is prettier, cooler and more romantic than New Haven. If they enter the theater in the right mindset, at worst, viewers will leave with a few new ways to describe their sex-crazed friends (i.e. “he’d shag an open wound”).

That said, aside from a brief but surprisingly lusty (and distinctively girly) make out scene, the film is strikingly unremarkable — save for coining “vagitarian,” a delectable addition to the pop culture lexicon of generation “O.C.”