Brad Pitt and Angelina Jolie's chemistry was so strong on the set of Mr and Mrs Smith that it didn't take long for rumours of an affair to start flying.
Brad - who turns 57 today - split from wife Jennifer Aniston less than 12 months later - and both he and Angelina initially denied any romantic involvement before admitting they'd 'fallen in love' during the 2004 shoot.
Indeed, Angelina's former bodyguard Mark Behar previously claimed he caught the pair "making out" in their trailers and that he helped pass notes between them, although both stars denied anything physical happened.
"[Angelina] and Brad were constantly laughing and flirting with each other and acting like two school kids who had the hots for each other, and it was so cute," he told Us Weekly.
"I caught them several times in each other’s trailers making out. I wasn't shocked at all when they got married years later."
And other on-set sources claimed Angelina teased Brad by secretly removing her flesh-coloured underwear during one love scene.
"In the end, she shunned the suit and climbed in bed with him naked! It’s the biggest thing we all remember from that film," the source told Us Weekly of the claims that have never been addressed by Angelina.
Angelina opened up about her courtship with Brad in 2006, insisting she had no intention of stealing him from Jennifer.
The actress - who shares six children with Brad - said that when they first met, "it was clear he was with his best friend, someone he loves and respects."
She told Vogue: "And so we were both living, I suppose, very full lives... I think we were the last two people who were looking for a relationship. I certainly wasn’t. I was quite content to be a single mum."
According to Angelina, she and Brad quickly "became a pair", finding "joy" in everything they did together.
Admitting she "couldn't wait" to get to work each day, she insisted it wasn't until filming ended that they began to contemplate a relationship.
“It took until, really, the end of the shoot for us, I think, to realise that it might mean something more than we’d earlier allowed ourselves to believe. And both knowing that the reality of that was a big thing, something that was going to take a lot of serious consideration," she said.
"We spent a lot of time contemplating and thinking and talking about what we both wanted in life and realised that we wanted very, very similar things."
They remained "very, very good friends", but when Brad and Jen announced their split in January 2005, Angelina said that's when things changed.
"Then life developed in a way where we could be together, where it felt like something we would do, we should do," she told the fashion bible, in an interview Jennifer would later brand "uncool".
“There was stuff printed there that was definitely from a time when I was unaware that it was happening," she said.
“I felt those details were a little inappropriate to discuss. That stuff about how she couldn’t wait to get to work every day? That was really uncool.”
Brad and Angelina Jolie's romance broke Jennifer's heart, especially when Ange fell pregnant so quickly.
In an unearthed Vanity Fair interview from September that year, Jennifer, then 36, wore her pain on her sleeve when the interviewer broached rumours that Angelina was expecting just two months before Jen and Brad's divorce was even finalised.
Describing how the actress looked like she had been "stabbed in the heart," the reporter said Jen cried silently for several minutes, unable to stop the tears rolling down her cheeks before shaking her head, too hurt to give an answer.
As for whether she believed the gossip that Brad and Ange had had a full-blown affair, Jennifer said, “I choose to believe my husband. At this point, I wouldn’t be surprised by anything, but I would much rather choose to believe him."
The line from friends was that he'd wanted to work out what he wanted in life - as a single man - and that he assured Jen, "This is not about another woman."
However, the strength of her belief was shaken when pictures surfaced of Brad playing the doting dad to Angelina's adopted son Maddox on the beach in Africa on April 29.
“I would be a robot if I said I didn’t feel moments of anger, of hurt, of embarrassment," Jen said. “I just don’t know what happened. There’s a lot I don’t understand, a lot I don’t know, and probably never will know, really.
“I have to think there’s some reason I have called this into my life,” she added. “I have to believe that - otherwise it’s just cruel.”
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