Channing Tatum, Matthew McConaughey and Joe Manganiello admit to a few nerves on the set of Steven Soderbergh's male-stripper-centric film.

"It's harder than anyone thinks for guys to actually be sexy."

Channing Tatum (No. 50 on Empire magazine's list of 100 Sexiest Movie Stars) was on the back patio at Cinema Bar in Culver City, commiserating with Matthew McConaughey(People magazine's "Sexiest Man Alive" in 2005) and Joe Manganiello (No. 1 on Men's Health magazine's best Summer Bodies of 2011).

Although a heady cloud of easy charm and testosterone was forming spontaneously above the picnic table, slowly expanding and intoxicating any females in proximity, Tatum elicited enthusiastic nods from his fellow actors as he explained just how much work it takes for guys like them to be sexy — especially when they're nearly naked. And oiled. And onstage. Gyrating.

"Girls can just do it, just walking. ... Guys, it's not the same thing. Especially when you put them in a thong," Tatum insisted. "Everything you're trying to do to be sexy makes you look like a clown. I challenge any guy to go and try to be sexy to his girl. ... It's a very humbling experience."

Many a gaggle of gal-pal moviegoers will be happy to render a verdict on the issue come Friday, as the three bare nearly all in Steven Soderbergh's male-stripper film "Magic Mike." (TheWarner Bros. movie will have its world premiere Sunday night at the L.A. Film Festival.) Inspired by Tatum's brief turn in the world of exotic dancing in Tampa, Fla., in his late teens, "Magic Mike" features McConaughey as the male revue's fire-breathing emcee, Manganiello as lady killer Big Dick Richie and Tatum as the show's main attraction, Mike.

On the surface and in trailers and other advertising, "Magic Mike" seems like nothing but a raucous bachelorette party relocated to a cinema. Soderbergh loads the front half of the film with copious amounts of fun, flesh and flamboyance. But the back half mellows into melancholy as Mike initiates a young dancer dubbed the Kid (Alex Pettyfer) into the troupe and the newcomer moves toward center stage.

Mike's budding romance with the Kid's sister (played by Cody Horn, daughter of new Disney studio Chief Alan Horn) pushes him to reexamine his life choices.

Soderbergh sparked to the idea of a male stripper movie when he was filming"Haywire"with Tatum last year in Spain. "I told him about this eight-month period in my life, and he was like, 'You've got to make that film.... You should write it for sure,'" Tatum recalled. "And I was like, 'OK, Steven Soderbergh, I'll get right on that.'"

Tatum's producing partner, Reid Carolin, did get on it, penning a script, and the shoot came together quickly last fall as the prolific Soderbergh had a brief window of availability between his other projects. Carolin and Tatum, along with veteran Soderbergh producers Gregory Jacobs and Nick Wechsler, scraped together about $7 million, the director said, and embarked on a rapid 25-day shoot in Southern California and Tampa.

McConaughey, 45, said it didn't take much for Soderbergh to persuade him to come aboard. "I got the call and talked to Steven, and within 10 minutes when he pitched it to me, I was on my knees in my kitchen, banging the floor, laughing," he recalled. "I love the idea of these corny little subcultures and worlds, and Steven's great at it."

Manganiello, who's well known as the werewolf Alcide Herveaux on the HBO series"True Blood"and recently played a buff object of envy in the movie"What to Expect When You're Expecting,"was a bit more hesitant.

"The clothes come off a lot on 'True Blood' so there was a sense of 'OK, when am I going to have my shirt on again?'" Manganiello, 35, said. The actor said he consulted his "What to Expect" costar Chris Rock on the decision, telling him, "I don't know, because my shirt's off again, and I just think dudes are going to hate my guts if I don't put a shirt on soon. And Chris was like, 'Guys are going to hate your guts anyway. Brad Pitt spent 15 years with his shirt off. He's doing fine.'"

With the cast in place, learning the choreography was the next major hurdle. Alison Faulk, who has worked with the likes of Britney Spears, Madonna and Pink, designed the routines — everything from a trench coats-and-umbrellas dance performed to "It's Raining Men" to a classic fireman-in-suspenders number.

"I'd never danced," said McConaughey, who also sings in the film. "We know one thing, it ends up with clothes off. I was thinking, there will never be enough time. I could rehearse this thing for 10 years."

Even the experienced Tatum, 32, confessed to nerves. "I'm about to go on stage and dance for the first time, and I'm like, 'Why did I want to do this again? This is completely not what I remembered.' I was terrified."

But once onstage, the actors said, a pleasurable trance sets in. "You've got anxiety, there's fear, but you've got pride and you're like, man, I worked this, I want to nail this," McConaughey said.

It's the coming off stage, said Manganiello, that's more painful. "For me, it was like coming out of a blackout. You get up there, you do this thing, and then it was like waking up the next morning covered in blood and having no recollection of what the hell you just did," he explained. "You're sitting backstage after your routine, in a thong, sweating, the music is over, you're just sitting there alone in silence ... going 'What did I just do? People are going to see this!'"

The dozens of women who got to play bit parts as club patrons were more satisfied than your typical group of extras, Soderbergh laughed. "The first time we shot [the 'Raining Men' routine], it was with 110 extras. These women were very happy. We had a lot of return extras — like 96%, which is unheard of on a movie."

At one point, one woman got a bit overzealous and reached for McConaughey's thong. "I remember feeling it go boom," he said, "and just as the cool draft was going a little further than it had been, I went, 'Oh, yep,' and tucked into a roll."

"He was kind of asking for it," Soderbergh said. "That was entrapment. He was provoking them."

"Magic Mike" is hardly McConaughey's only provocative role this year. Moviegoers will next see him as a hit man in William Friedkin's NC-17 rated "Killer Joe," and later in the year he'll turn up as an enigmatic vagabond in Jeff Nichols' "Mud" and as a kinky newspaperman in Lee Daniels'"The Paperboy."

Tatum has been busy too. Besides appearing in "Haywire," he's already had two blockbusters in very different genres this year —"The Vow" (a romance) and "21 Jump Street" (a buddy comedy). It's a far cry from his days as a dancer in Tampa, when Tatum said he typically took home about $150 a night. Although his character in "Magic Mike" spends more than six years dancing, Tatum in reality lasted less than a year in the male revue.

"You get in at 18, and halfway through 19 you look around and you're like, 'Man, I don't want to do this.' I never really enjoyed taking my clothes off. That was a weird thing," he said. "I really enjoyed the dancing, the performance of it all, the craziness of the life. But I would always take my pants off and run off stage."

As the Kid becomes more central to the troupe, Mike realizes that he wants out of the club scene. He has dreams of running his own custom furniture business. "I think everyone's been in a situation where they're like, 'What do I do now? What do I do with my life?'" said Tatum.

It's certainly a theme that struck a chord with Soderbergh, who has been saying for years that he wanted to exit the filmmaking world and engage in other artistic pursuits. Now 49, he insists that "Magic Mike" will be followed by just two more movies — "The Bitter Pill," about a woman who develops a prescription medication habit, also featuring Tatum, which recently wrapped filming, and a Liberace biopic with Michael Douglas that starts production in July. After that, he plans to write a book and stage at least one play.

"The Kid is kind of a mirror for" Mike, said Soderbergh. "As a result, he starts to reconsider where he is. He thinks the Kid is like him, but then realizes that he's not. The more he sees of it, the more he needs to make a change."

"Obviously, this is really my change too. It's just time to reboot."

julie.makinen@latimes.com