Breaking Up...

...Is Fun To Do.

You've read all about them in the tabloids and watched Lord-knows-how-many reports about their romance on TV. But here's one fact about Vince Vaughn and Jennifer Aniston that you probably haven't heard a lot: They make one hell of an odd couple.

That was evident earlier this month, when the actors took separate breaks at separate ends of Los Angeles to discuss the romantic comedy on which they met a year ago.

On a sunny Tuesday afternoon, Aniston breezes into her luxurious office in Beverly Hills and snags a bottle of water that her assistant has set out on the counter. The bright room contains stylish furnishings and expensive works of art. A natural sisal area rug emits the faintest smell of hay. Aniston is tan and looks uncommonly healthy, and she wears a casual vest that exposes her trim arms. She smiles and perches herself attentively on the edge of a white sofa, ready to answer queries about her life and career, which she does with succinct words and refreshing frankness.

Twenty-four hours later, Vaughn appears in the doorway of his dim workplace in the San Fernando Valley. A bare desk crowds one corner, a TV sits askew from the wall, and a Wedding Crashers poster rests on the floor. The room smells like stale tobacco. Wearing a Notre Dame T-shirt, his hair mussed, he sinks his imposing 6-foot-5 frame deep into a brown rec-room couch, taps on a pack of cigarettes, and fires up a smoke. He's never enjoyed sharing details of his personal life, he notes in his rapid, punctuation-averse cadence, but he offers to try: "Feel free to ask me anything."

Hey, man, don't worry, we will.

As ironic titles go, The Break-Up is a doozy. It's a story about a man and a woman who fall out of love... and it stars a woman coming off one of the most publicized divorces in history. Aniston's split from her husband of five years, Brad Pitt, and his concurrent union with Angelina Jolie were all anybody seemed to be talking about when The Break-Up began shooting last summer. Paparazzi followed Aniston's every move. But when it grew clear that she and Vaughn were becoming more than mere colleagues, the media turned up the heat full blast. To this day, the actors are trying to keep their relationship quiet. But their unmitigated failure to do so has made The Break-Up one of the most buzzed-about films of the summer.

And yet, even without all the artistic imitations of life, The Break-Up - about a Chicago odd couple who split but refuse to leave the condominium they jointly own - would have been news: Opening June 2, it's one of Hollywood's few hopes for a breakout romantic comedy this summer, and it features two big stars with a lot to prove.

Vaughn, 36, has bounced around Hollywood since the early 1990s, weathering years of rejection and failed movies like Psycho and Domestic Disturbance. Not until the smash success of Wedding Crashers last summer did he fulfill the promise of his memorable turn in Swingers a decade earlier. During the past year, he's become one of Hollywood's most in-demand talents: He's now commanding $20 million to play Santa's brother in 2007's Joe Claus, and he has the clout to assemble projects like his live road production Vince Vaughn's Wild West Comedy Show. The Break-Up - which he conceived with the first-time screenwriters Jeremy Garelick and Jay Lavender three years ago, sold to Universal with the guarantee of a hefty $50 million production budget, and made in his native Chicago - could solidify both his audience appeal and his industry power. "This marks a big moment in his career," says Jon Favreau, Vaughn's longtime collaborator and pal, whom he met on 1993's Rudy and who appears in The Break-Up as his best friend. "This is a movie that he put together on his own. He produced it. He came up with the story and hired everybody. He really made something happen."

Vaughn and Aniston never met - and Vaughn won't cop to any long-distance crush - but the actress was always key to his vision for The Break-Up. "I had her in mind when I was writing, because I wanted someone who was good with comedy but also a good actor," he says, referring to her ability to modulate between moments happy and sad, of which there are plenty in the film. "There was no second choice."

So after hiring director Peyton Reed, whose spirit he admired in Bring It On and Down With Love, Vaughn set about piquing her interest. The filmmakers swear that Aniston's real-life woes has nothing to do with their decision to approach her. "It wasn't like anybody was saying, 'Who's an actress who's going through a really painful public breakup that we could cast in this movie?'" Reed recalls with a chuckle. Still, getting her attention wasn't easy.

ANISTON Everybody was so nervous to come to me with a movie called The Break-Up, thinking, Well, she'll never do that! I went, "You've gotta be kidding. Really?" Of course, with me, I didn't think, How dare they? I actually thought, That sounds really funny.

EW How did you come to the resolution where you said to yourself, "Okay, I can do this"?

ANISTON I didn't know I could. I didn't want to take advantage of [my divorce]. But then I thought, Well, there's a reason this movie came to me at this time.

EW Would you say doing this movie was cathartic?

ANISTON It was. It's not always you have the opportunity to go through a breakup and then shoot a movie called The Break-Up. I just find it luck, truthfully. Good luck. Because you're able to exercise something quicker. I had a little bit of a well to dip into.

'The Break-Up' went before cameras in Chicago last June. The shoot was pretty quick (46 days) and apparently pretty happy. During her spare time, Aniston explorer the city's architecture and savored a sloppy late-night hot dog at the legendary haunt the Wieners Circle, while Vaughn hit some jazz clubs, quit smoking, and packed on 25 pounds. But with the June 10 premiere of Mr. & Mrs. Smith (which, by pure coincidence, featured Vaughn in a supporting role) and revelations that Pitt and Jolie had become a couple, the focus on Aniston and her new flame intensified; in the salacious ongoing tabloid narrative that ensued, The Break-Up emerged as a sort of bizarro twin of Mr. & Mrs. Smith.

Over the years, Aniston has grown accustomed to the tabloids trailing her every move - "You've gotta have goals," she deadpans. "You gotta have something to do, so you may as well stalk people" - and claims that her experience in Chicago was par for the course. "In terms of Jen's attitude at work," Reed says, "I would not have known it was going on because she has this extraordinary ability to shake it off."

The firestorm was something new for Vaughn, however; until then he has succeeded in keeping a lid on his private life. (Even now, all we know for absolute sure is that he once dated Joey Lauren Adams, his costar from 1998's A Cool, Dry Place, who appears in The Break-Up as Aniston's best friend.) Perhaps that's why he took up smoking again at the end of the shoot - and consequently lost the 25 pounds he'd gained during production. Still, he hopes people just want to see him and Aniston happy. "You can't really be like, 'Oh, I'm an actor, I'm being followed by the paparazzi and it's horrible.' I just think that there's a bounty for a picture, and if that gets higher they're prepared to do more and more," he says, philosophically. "In the scheme of life, it's ridiculous."

Vince Vaughn and Jennifer Aniston are dating. Exactly. Can't we just go and say what everyone already knows? Because darned if they will, even if their behavior - be it in reports of them looking at property together in suburban Chicago or merely in the way they speak about each other - indicates the contrary. Reed refers to the relationship as "whatever may or may not be going on."

Aniston is even more cryptic, calling it "the stuff that's happening." As for Vaughn, remember when he invited us to ask him anything?

EW Are you and Jennifer dating?

VAUGHN You know, here's my answer to that stuff. I'm not a person who discusses all the ins and outs of what's going on with me ad nauseam, because I feel like it betrays something that's mine, that's special to me. It's private, it's my stuff. Ultimately, if people know or don't know it won't change their lives. And it's not out of not being happy about something or proud or excited. It's just not what I do. I've [never discussed] girls I was dating. I felt that that's a good way to hurt a relationship.

EW Do you get tired of the questions?

VAUGHN I truly don't. I've obviously dealt with this a lot recently and I don't tire of it because I would do the same. It's something that people are curious about and I totally understand it. I just always have chosen to keep my private stuff to myself.

EW How do you respond to the suspicion that you and she actually are not an item but that you just let all the buzz continue in order to generate interest in the movie?

VAUGHN [smiles] That's not my style with stuff.

Still, nobody can deny that the buzz around their relationship is integral to the movie's success. "Just about everyone knows this movie is coming," says Universal Pictures marketing president Adam Fogelson, who adds that such awareness makes filling seats much easier. "All the attention that Vince and Jen have gotten over the last many months is substantially responsible."

From Eyes Wide Shut to Bounce, Vanilla Sky to Sahara, movies with romantically linked leading couples litter the recent cinematic landscape - and their box office results are as erratic as most of the relationships themselves. Russell Crow and Meg Ryan's real-life tryst seemed to turn viewers off from Proof of Life. But Mr. & Mrs. Smith became a $186 million hit largely because ticket buyers were eager to revel in the delicious spectacle of Pitt and Jolie trying to kill each other right when news of their affair was exploding. Will that scenario prove a harbinger of The Break-Up's success? It's possible. No matter what, though, these "office romances" surely put increased strain on both the stars and their relationships.

A small statue of Avalokiteshvara, the Buddhist goddess of compassion, sits high on a shelf, presiding over Aniston's office. It's easy to guess why Aniston might find that statue reassuring just now. She has a major movie opening that could mark a turning point in her career. She's coming off a tough divorce. She's almost a year into a relationship that's under major scrutiny. And the fact that people will be watching The Break-Up to get a sense of her chemistry with Vaughn disappoints her. "I didn't shoot this movie so that people would go see it because it reflects what's happening in my private life," she says. "I'd like to be given a little bit more credit. I know that that's been said, but I don't give a s--- what people think. I do parts based on what speaks to me and what I feel I could do a good job at. This just happens to be that."

Aniston has largely been painted as the victim in her divorce. But her decision to play a spurned and sometimes vengeful lover in The Break-Up, she makes clear more than once, was not retaliation. She doesn't have much to say when the conversation drifts to her split with Pitt - "There's nothing that's new information" - but, understandably, it's still very much on her mind. During the course of our interview, she returns to the subject regularly, always in vague and general terms like "past stuff" and "all of this". She utters the name "Brad" once, but only in passing.

As the conversation winds down, Aniston gets up to fetch ice from the freezer. She returns to her seat, pops open a diet root beer, and addresses her future while watching her soda fizz over ice.

With no projects lined up right now, she's looking to take a break. She says she used to love L.A. sunshine, but life here under the shadows of zoom lenses has grown dreary. She smiles and speaks with striking optimism about fleeing the city and the "stalkerazzi" soon - maybe to Chicago, where Vaughn lives in his spare time, maybe somewhere else. Just... out. "This can't be the only place to live," she says. "There's so much dark, it's nice to have some light."

1999 Office Space She had flair to spare in this ode to Dilberts everywhere. That it now has a cult following, she says, is "insane!"

2002 The Good Girl Aniston earned the first strong reviews for her film career for this indie about two depressed retail clerks.

2003 Bruce Almighty Her biggest box office hit yet. As Jim Carrey's loyal girlfriend, she largely stood by while he did his God thing.

2005 Rumor Has It This failed spin on The Graduate brings back bad memories: "It was a problem child from the beginning."

2006 Friends With Money "It was the perfect time to play a zombie," Aniston says of portraying a down-and-out maid during her divorce.

VINCE VAUGHN, FROM 'SWINGERS' TO STAR

1996 Swingers Our boy is "all growns up!" It's been 10 years since he and Jon Favreau broke out and redefined the word money.

1997 The Lost World: Jurassic Park When Steven Spielberg cast Vaughn as a dino trekker, he dubbed him a "future icon."

1998 Psycho Vaughn's ill-fated portrayal of Norman Bates continued a five-year run of dark - and critically drubbed - movies.

2003 Old School His big return to comedy. "DreamWorks was reluctant to cast me: 'He's not a comedic actor anymore.'"

2005 Wedding Crashers Vaughn thought he'd made a good movie with Owen Wilson, "but I didn't know it would do what it did!"