My thought on today

Smith returns with heartfelt grossout “Zack and Miri Make a Porno”

Elizabeth Banks and Seth Rogen are porn stars (in their own minds) in "Zack and Miri Make a Porno."

Comedian Rita Rudner once remarked that before meeting her husband she’d never fallen in love but had “stepped in it a few times.” The same can be said of the hapless title characters in writer/director Kevin Smith’s pottymouthed, big-hearted “Zack and Miri Make a Porno.” Pals Zack (Seth Rogen) and Miri (Elizabeth Banks) spend 10 years stepping in mistakes only to realize — with the help of the chummiest porn film crew ever — they could have fallen into something big.

And such, too, is the case with Smith, who catalogued a few missteps of his own with the shamelessly sentimental “Jersey Girl” and the sorta-funny but mostly disappointing “Clerks II.” With its endless parade of raunchy sex gags, full-frontal nudity (female AND male), bodily fluid jokes and profanity-laden dialogue, though, “Zack and Miri” is no misstep. If anything, it signals something big: the return of an artist reclaiming his favorite medium.

That’s not to say “Zack and Miri” is perfect; it’s just the perfect Kevin Smith rom-com. Consider the left-of-center plot: Twentysomething roommates Zack and Miri, friends since first grade, share a rundown Pittsburgh apartment that lacks decoration and, thanks to some frivolous spending on sex toys, both electricity and running water. Dejected, Zack and Miri hole up in a dive bar to regroup, and Zack hatches his “brilliant” plan: He and Miri can — you’ll never guess! — make a porno, distribute it to their senior class (they’ve got the mailing list since they just suffered through their 10-year reunion) and make a bundle, or at least enough to turn on the water and power.

True to form, “Zack and Miri” succeeds because Smith dusts off a few of his trademarks (which, I suspect, must have been tucked away in storage since before “Jersey Girl”). First, there’s the “shock and awe” dialogue. Granted, these days the F-word is hardly shocking, but Smith’s script includes enough of it — and several other choice four-letter words — that it’s a wonder the film wasn’t slapped with an “NR” rating. But Smith mixes the profane with the profound, throwing in a few insightful lines (Zack and Miri’s attempts to name their porno; Miri’s riff on “period panties”) that make the profanity easier to take.

Another Smith hallmark? A cast of wacky secondary characters that amps up the comedy and, on occasion, provides unexpected insight. Smith newcomer Craig Robinson gets some of the film’s biggest laughs playing Delaney, an unhappily married man who just wants “to see some free titties.” (He should, henceforth, be known as Craig Robinson, not That Warehouse Guy from “The Office.”) Real-life porn stars Katie Morgan (Stacey, an airhead stripper) and Traci Lords (Bubbles, who got the name because she can blow bubbles using her … uh, best you find out for yourself) have cameos, and Jason Mewes (a.k.a. Jay) manages to make his character, a legend-in-his-own-mind womanizer, somehow likable. Even Randall (Jeff Anderson) of “Clerks” fame shows up to join the fun … and ends up with something (hint: it’s not egg) all over his face.

And, of course, there are the leads we can’t help rooting for. Rogen’s managed to make being a pudgy, schleppy dork ubercool, even sexy, and he revives that routine here to great comic effect. He’s exactly right to play the guy you never knew you always wanted. Banks, who’s slowly come into her own as a comic actress, hits all the right notes as a high school dweeb-turned-hot chick who hasn’t quite grown into her new skin. (Put glasses and some overalls on her and she could play the Pretty Ugly Girl in yet another teen movie spoof.)

A few critics have argued Banks and Rogen don’t generate much romantic chemistry; I beg to differ. There are sparks there, but they’re the kind expected of two people who stumbled into something life-changing but totally unforseen. Their interactions are a bit awkward, halting, tentative; Miri says the wrong thing, Zack fumbles with a button, and neither wants to admit what’s going on. But all that culminates in the one of the sweetest, most believable sex scenes ever filmed. The reason? There’s no trace of artifice in the entire sequence; every part of it feels real (well, as real as it can considering it’s Seth Rogen and Elizabeth Banks, not Zack and Miri). They say the wrong things, they can’t find this zipper or that belt loop, they don’t know where to put their hands. It’s awkward and ungainly, but in a way that’s completely disarming, funny and endearing.

That said, “Zack and Miri” has its share of flaws. At 112 minutes, it’s a bit long-winded, the feces jokes get old after, oh, about 30 minutes, the “serious talk” moments fizzle and the ending is disappointingly predictable. But every minute of “Zack and Miri” is vintage Kevin Smith, and that alone is cause for celebration. And that, as Banky might say, is cause for a “shared moment.”

Grade: B+