The new Cameron Diaz comedy “The Sweetest Thing” desperately wants to appeal to a pair of demographics with as much in common as the NRA and PETA: the teenage girl and boy. On the one hand, it is an estrogen-packed girl-bonding road-trip date flick that explores confusion and embarrassment on the quest to find that special someone. At the same time, it is a breast-grabbing, penis-poking, toilet-soaking, butt-pinching, gross-out soft porn “There’s Something About Mary” rip-off with more oral sex than the Ken Starr report and my local Catholic church combined.

Since I have two younger sisters and I am barely past the realm of teendom, I can safely say that both genders will get everything they need from this film. There’s plenty of Cameron in her underwear, balanced nicely with girl talk, dancing, gooey love, and just plain gooey (it’s in the spirit of the film I’m reviewing, folks!).

Now please indulge me briefly while I give you my annoying, pompous critic’s perspective: it is not a work of art. It has a plot with as much substance as a soft porn flick. It has characters with the depth and humanity of a dinner theater production of “Who Stole My Overalls?” While it produces a few giddy, silly moments, it often mistakes “clever” and “outrageous” for “ridiculous” and “awkward.”

That said, anyone who goes to see a film that wears its fluff on its sleeve expecting a brilliant examination into the depths of the early adulthood needs to have their head examined. And I’m not going to write a really bad review: that would be like yelling at a cute, fuzzy puppy for peeing on the rug.

Diaz plays Christina Walters, a man-eating “player” with an intense fear of commitment who’s looking for “Mr. Right Now” instead of “Mr. Right.” She works in advertising (like that matters), and spends her free time hanging with her best girl friends, Courtney (Christina Applegate) and Jane (Selma Blair), partying at hip, exclusive dance clubs, checking out men, and talking in some sort of ditzy girl code language.

Her freewheeling ways fall apart when she runs into Peter (Thomas Jane) at a club and falls big time. Pretty soon she’s sobbing over “The Ten Commandments of Love,” bemoaning her “rut” in the single life, and skipping town with Courtney to crash Peter’s brother’s wedding. She decides that it is time to settle down and be happy.

Anyone who actually read those last two paragraphs wasted their time. The film meanders on various tangents for half the running time, skipping from random road trip fiascos to one spectacular oral sex/sing-a-long/penis-piercing crisis that will never allow you to listen to Aerosmith’s “I Don’t Want to Miss A thing” with any sort of pure enjoyment. There is one gag involving stains and dresses that may actually be straight out of the Ken Starr report. The plot is really just a ploy for a pervert to translate his sick, demented thoughts on to the big screen.

Transitioning once again from bitchy critic mode, “The Sweetest Thing” does enough right to be a not-too-painful 90 minutes. For one, Cameron Diaz is a winner no matter how many ways you slice it. She has a goofy, sweet charisma that cannot be faked (believe me, many have tried — Heather Graham, get on a bus, go back to Hicktown, USA, and be a milkmaid), and she can be a truly brilliant actress in the right film, such as the twisted “Being John Malkovich”.

For another, the rest of the cast melts together like butter. Christina Applegate has graduated from a silly “Married–With Children” ditz with a degree in perfect comic timing. She even gives the inane dialogue some subtle wit, like when she tries to divert a gawking young boy’s attention in church by pointing to the ceiling and whispering: “Look! There’s Jesus!” Selma Blair weaves similar gold from dry straw: she gets all the forced, “outrageous” buzz moments, yet she infuses them with a virginal vulnerability that makes them uncomfortable but comical.

As the unfortunate fourth-wheel male lead, Thomas Jane is good enough to hold his own — he and Diaz have a cute chemistry despite their minimal shared screen time (another story flaw). He gets considerable support from the very funny Parker Posey, as a nervous bride, and the even funnier Jason Bateman, as his immature brother Roger.

Thanks to this fun ensemble, “The Sweetest Thing” can honestly be classified on your “smarter than a porn film” list. Despite all the factors that normally constitute a “bad film,” it manages to traverse genres (gross-out and romantic), and it squeezes a few reluctant laughs. It really is hard to hate that cute little puppy, no matter how many times it craps on your bed.