By Caroline Briggs
Entertainment reporter, BBC News
When Jennifer Aniston received the script for her latest film The Break-Up, it must have felt like art was mirroring her own life.
The Break-Up follows the story of a seemingly happy couple
At the time the former Friends star was going through her own high profile break-up from her then husband Brad Pitt.
But the 37-year-old agreed to team up with Vince Vaughn in the bittersweet comedy about a couple reaching the end of their relationship.
Vaughn, who also wrote and produced the film, is the first to admit the subject material means the film is not your average comedy.
He said he decided to write the so-called "anti-romantic comedy" as reaction to the "disappointing" scripts coming out of Hollywood.
"They were all the exact same story told again and again: perfect people, saying the exact right thing, almost some kind of magical world they live in," he said.
"Or they had some kind of subplot, for example 'OK, if you don't marry a girl in the next six months you will not inherit my company, and I'm going to leave it to this mean guy who works for me'.
"Relationships are kind of strange enough as they are."
Vaughn and Aniston play Gary and Brooke - a couple who let a seemingly small argument over lemons escalate out of control.
Suddenly they find themselves, after two years together, confronted with the choice between love and loss.
War breaks out when both Gary and Brooke fight to keep their shared condo for themselves.
One scene in the film called for Aniston's character to walk naked through the living room.
Vaughn said the scene was necessary for the "dynamic" of the film, but Aniston has admitted it was a difficult scene to tackle.
"When I read [the script] it seemed so long and extensive... she walks down the hallway, she walks through the living room in front of the television, goes into the kitchen, opens the fridge, gets out a cola, goes back.
"I don't even walk around my own house naked for that long!
Gary and Brooke implode after an argument about lemons
"I though 'this is going to be a NC-17 rating, there is no way they can shoot that!
"And then sure enough they figured out a way to shoot it very tastefully and it was not gratuitous in any way."
Vaughn joked it had been a "really easy" scene for him to film.
"That was probably my favourite day's filming. I thought you were a brilliant actress that day Jennifer," he said.
Since Aniston's high profile parting and subsequent divorce from Pitt, rumours about a relationship with Vaughn have been tabloid fodder.
But both seem happy to keep their relationship strictly a case of "are they, aren't they" speculation.
The pair rarely pose for photographs together and have worked the red carpet separately at the film's premieres.
But open the pages of any magazine and they are often pictured in each other's company.
The pair were even photographed together in the days following the birth of Pitt's child, Shiloh, with actress Angelina Jolie.
While Aniston is happy to chat about her co-star, it is obvious it is one she likes to keep strictly professional.
She said it was "fun" working with him on the film which topped the US box office in its opening week.
"You do feel like you're acting with a tennis pro, and there is just a nice volley back and forth," she says.
While Aniston quickly bats away questions about her private life, speaking in the context of the film gives a glimpse into her views on relationships.
"[The film] is not just about pointing out how men have their downfalls, I think it's about how women too have their downfalls and how men and women communicate differently.
"And what the results are due to a lack of communication and then how things fester and grow and build and until something threatens to break the camel's back.
Vince Vaughn starred in The Wedding Crashers with Owen Wilson
"People have come up to me and said it's like holding a mirror up to their relationships."
The Break Up is one of a number of films Aniston has starred in since the hugely successful Friends ended in May 2004.
Her roles in films such as Rumour Has It and Derailed were generally derided by the critics, and Aniston admits some performances fell short of her own high standards.
"We don't walk into a job knowing if it is going to be a success or a failure, but I think we are all hoping that something is going to hit the wall and stick," she said.
"There have been a lot that we read that are just so far-fetched and outrageous and unrealistic, and I've done them, and I don't feel like I performed very well in them.
"So [The Break-Up] was way overdue for me, I was just waiting for something that I responded to.
"It's just a wonderful, simple story about two people, and they just don't come along very often."
The Break-Up opens in cinemas on Friday 21 July.