Brad Pitt and Angelina Jolie immediately sparked romance rumors as soon as they started filming "Mr. and Mrs. Smith" in 2004.

Both stars denied that there had been a "dastardly affair" between them. They also tried to stop the rumors from spreading since Brad, at that time, was still married to Jennifer Aniston.

Although Brad's infidelity seemed to be controversial enough, what Angelina did during a sex scene with the actor caught more attention.

An on-set source revealed to Us Weekly that Angelina reciprocated Brad's flirting and seduced him. Another insider seconded the statement and claimed that they saw her secretly removing her flesh-colored 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 said, confirming that Angelina climbed into bed naked with Brad when he was still married to the "Friends" actress.

Even Angelina's former bodyguard, Mark Behar, confirmed that he witnessed how the pair "made out" in their trailers and that he used to pass x-rated notes between them.

"[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," Behar 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."

A few months later, the "Maleficent" actress finally admitted that they fell in love with each other during filming.

"It took until, really, the end of the shoot for us, I think, to realize that it might mean something more than we'd earlier allowed ourselves to believe," Jolie said. "Both knowing that the reality of that was a big thing, something that was going to take a lot of serious consideration."

What hurt Aniston, however, was the fact that Angelina got pregnant with Brad before they had finalized their divorce.

Angelina Did Not Mean It?

In 2006, Angelina opened up about her relationship with the "Fight Club" actor and insisted that she had no intention of stealing him from Jen.

"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," the actress said.

She added that they became a pair after they found joy in each other and in everything they did together. Since they developed romantic feelings, she was always very eager to get to work every day.

Despite that, Angelina clarified that they only talked about their relationship after the filming of "Mr. and Mrs. Smith" ended. They remained "very, very good friends" afterward, but when Brad and Jen announced their separation in January 2005, that was when things reportedly changed.

After years of being together, Angelina filed for dissolution of their marriage in 2016 due to irreconcilable differences.

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