Wiig gets real in ‘Bridesmaids’

Kristen Wiig has just come off an average Saturday night, one that required her to wear a 2-foot-high wig, shuffle lethargically around a stripper pole and bury her face in Helen Mirren’s cleavage.

“I was like, ‘Are you cool with this? ‘Cause I’m really gonna get in there,’ ” Wiig said of rehearsing the “magical bosom” scene with the 65-year-old British actress.

“She was like, ‘Oh yeah. Do whatever you need to do and stay in there as long as you want.’ And I did. It’s pretty intense in there.”

Since joining the cast of “Saturday Night Live” in 2005, Wiig has emerged as one of the sketch comedy show’s most valuable players for her exuberantly weird characters, including the world’s most enthusiastic Target checkout lady, the freak sister in a family of Lawrence Welk singers and a bug-eyed Nancy Pelosi.

Now, at 37, she is shedding the goofy costumes, accents and outlandish behavior to attempt that trickiest of parts – a real person.

Wiig’s first leading big-screen role is in “Bridesmaids,” opening today, which she also co-wrote.

“All my characters are someone you don’t want to talk to at a party,” said Wiig, who off-stage is surprisingly introverted for a woman who makes her living wearing snaggle teeth and doll hands.

“It’s always that person who’s being too loud, doesn’t have any social boundaries or says the wrong thing.”

In “Bridesmaids,” she plays a relatively normal, single thirtysomething woman whose life is thrown into disarray when she’s asked to be the maid of honor by her best friend, played by “SNL” alumna Maya Rudolph.

A pastry chef whose bakery has gone under, she crafts intricate cupcakes for no one and moves back in with her mom in a state of financial and emotional defeat.

Rose Byrne of TV’s “Damages” plays an alpha bridesmaid, Melissa McCarthy of “Mike & Molly” is the groom’s crude sister and “Mad Men’s” Jon Hamm plays a gorgeous jerk.

Directed by “Freaks and Geeks” creator Paul Feig, “Bridesmaids” is the first female-driven film to come out of “The 40-Year-Old Virgin” and “Knocked Up” producer Judd Apatow’s mainstream comedy factory.

And though the broad outlines of the script by Wiig and her writing partner Annie Mumolo fit comfortably into the wedding genre, the execution is decidedly unladylike, with pratfalls, poop jokes and athletic sex.

“We wanted to write a comedy, not a female comedy, just a comedy that has a lot of women in it,” Wiig says. “There’s a difference.”

A native of Rochester, N.Y., Wiig moved to Los Angeles after studying art at the University of Arizona and developed her comic sensibility in four years spent at the Groundlings, the L.A. improv troupe whose members have included Will Ferrell and Conan O’Brien.

It was there that she honed some of her now-famous characters, including befuddled film critic Aunt Linda, the giggling, chirping singer Bjork and Target Lady, who is based on an actual clerk Wiig encountered at the discount chain’s Burbank store.

In her 20s, she paid her rent with odd jobs, including floral designing and acting in commercials (“Having to smile while holding a box of tampons wasn’t my dream,” she says).

Wiig joined “SNL” just after Bill Hader, with whom she shared a manager.

“I heard there was this new girl coming in from Groundlings,” Hader said. “I thought, ‘I’ll help her out, show her around.’

“I remember her first table read. I wrote this Vincent Price sketch and she proceeded to do a spot-on Judy Garland. … Immediately, it was like, ‘Ooh … she’s better than all of us. She’s Michael Jordan. She’s gonna be running the place.’ ”

Her first notable film role came in 2006 as a slutty mom in a little-seen film Feig directed called “Unaccompanied Minors.” But it was a small scene in “Knocked Up” in 2007 that won Wiig fans outside the “SNL” audience.

As a passive-aggressive E! channel staffer, Wiig told Katherine Heigl’s character, “We don’t want you to lose weight, we just want you to be healthy, by eating less.”

“I had never seen anybody stronger (working) with nothing,” says Apatow. “She created this amazing character and tore down the house.”

He asked Wiig if she had any projects in the works, and she and Mumolo began working on the script that would become “Bridesmaids.”

Wiig would go on to provide some of the most memorable laughs in the films “MacGruber,” “Adventureland” and “Paul,” and play a rare straight-woman role in the roller derby movie “Whip It.”

Between films and “SNL” seasons, she and Mumolo spent years honing their script. By the time they turned in their first draft, they had carefully shaped Annie’s emotional arc but neglected Wiig’s key comedic assets.

“There were stages where I felt Kristen was writing herself as a straight person too much,” Apatow says. “She was very comfortable giving others the joke. I had to convince her to give herself the joke.”

He and Feig added some of the movie’s trailer-friendly set pieces: a food poisoning breakout in a bridal shop, and Annie’s pill- and booze-addled meltdown on a plane.

Apatow, whose output has largely been devoted to the extended phase of twenty- and thirtysomething male adolescence, said he sees little difference between “Bridesmaids” and his other films besides all the skirts.

“We said, ‘We’re gonna make a great, funny movie that stars primarily women,’  ” he says. “If it works, men will come too.”