HOLLYWOOD -- At one time 'the love that dared not speak its name' referred to homosexuality.

These days it signals the rumoured tryst between Brad Pitt and Angelina Jolie.

Both actors have repeatedly denied they are, or ever were, anything more than good friends and dedicated colleagues.

Rumours began shortly after Pitt and Jolie began work on their summer action comedy Mr. and Mrs. Smith, which opens Friday.

There was speculation they were creating more sparks off camera than on.

For almost a year, Pitt and Jolie allowed gossip columnists on both sides of the Atlantic to speculate about how hot or cool their relationship has been.

It was only recently that Jolie spoke to the British press.

"I've been painted as the Wicked Witch of the West and a marriage wrecker. But all I've ever been to Brad is a shoulder to cry on," said Jolie

"Half the world believes we had an affair and I'm the one to blame for his split. But the truth is I was there to try to help him through his pain."

Jolie claims Pitt "longs to be a father and he's been in emotional turmoil for a long time because that hasn't happened for him."

She does not deny that they spent a great deal of their off time together during filming or that they met up in Africa recently when both were on assignment there.

"Brad loves my son Maddox. He is so good to him and Maddox was thrilled with Brad's attention."

Jolie has not commented on the reports she fought with director Doug Liman until they could no longer work together.

Pitt apparently stepped in to film the remainder of her scenes.

This purported affair and Jolie's rumoured spat with Liman are just two more in a series of hurdles Mr. and Mrs. Smith faced in going from screenplay to screen.

It was a spec script by an unknown writer that circulated in Hollywood for years.

Simon Kinberg had written it as his thesis for his degree in screenwriting at Columbia University.

His professor encouraged him to send it to agents in Hollywood, where it was snapped up.

It's the story of a bored married couple.

Each partner has no idea that their spouse is actually a skilled assassin.

Suddenly they are each assigned to kill the other.

Nicole Kidman was originally cast to star opposite Pitt but she had to pull out of the project when her flick The Stepford Wives ran way over shooting time.

Though he says Kidman is one of his favourite actors, Kinberg insists he was not devastated by her departure.

"Angelina is the better choice," says Kinberg.

"Nicole is a wonderful actress but it was always difficult for me to imagine her in the physical action this movie demands."

He says he always felt "Nicole was too cold for that part. Angelina has the sexual energy the role requires."

Kinberg was devastated when Pitt pulled out.

He had suggested his Ocean's Twelve co-star Catherine Zeta-Jones replace Kidman but she was unavailable.

It was not until Jolie signed onto the project that Pitt came back.

After early test screenings on the film, Pitt and Jolie were called back for reshoots and added scenes.

At an even later date, Angela Bassett and Keith David were added to the cast as Pitt and Jolie's respective bosses.

Kinberg's career does not hinge on the success or failure of Mr. and Mrs. Smith.

He is currently one of the hottest screenwriters in Hollywood.

He wrote the screenplay for Ice Cube's XXX2: State of the Union and worked on the final draft of The Fantastic Four.

"When I came to The Fantastic Four it was a month before they started filming. A script was already there," explains Kinberg.

"The action was all in place but the characters needed improvement. So that's basically what I did. I pumped up the characters a bit."

Kinberg has also written a screenplay for X-Men 3.

"This was the project with the most pressure," admits Kinberg.

"The first two X-Men films were very successful, so the pressure is on me as the writer to deliver good stories and new characters.

"I brought some ideas and they liked them. I am the first writer there. So we'll see what happens with this project."

He still hopes Mr. and Mrs. Smith is a hit because it is the script that means the most to him personally.

"I developed the story over a period of five years.

"There is so much of my heart in that film."