Toxic Love! How Jealousy & Competition Poisoned Brad & Angelina's Marriage

Brad Pitt and Angelina Jolie met on a movie set, but it was their respective careers that killed their marriage, an insider told RadarOnline.com.

Jolie filed for divorce from Pitt on September 19. As fans of the mega-movie stars know, they fell in love more than ten years ago while filming the 2005 movie Mr.& Mrs. Smith — while Pitt was still married to Jennifer Aniston. In the flick, Jolie and Pitt played a rich married couple whose competitive nature as assassins led them to try and destroy each other.

Now, a source close to the Jolie-Pitt clan told RadarOnline.com exclusively, "It was like life imitating art! They were always really competitive as actors."

At first, the source said, "It used to be healthy for their relationship that they are both driven. But over the course of the last year, the two of them have gotten extremely competitive in their careers, and not in a good way."

As previously reported by RadarOnline.com, Jolie, 41, has been focusing an increasing amount of time and energy into humanitarian work after being named as the UNHCR as a Goodwill Ambassador in 2012.

"Angie and the kids have been traveling the world without Brad for over six months, while Brad is focused on his current movie projects," the source told RadarOnline.com.

"Brad used to go with her on her missions and he would take care of the kids while she was doing her thing. But then he got booked for some big roles and all of that stopped," added the insider.

And non-stop cheating rumors on both sides didn't help. The source told RadarOnline.com, "The time away from each other just made their jealous issues so much worse!"