Published on: January 11, 2009

Angelina Jolie is terrified that Brad Pitt is planning to walk out on her because he has a commitment phobia - and that she will be left alone just like his ex-wife Jennifer Aniston.

Angelina tore into Brad after he recently referred to Angelina as "the woman I'm with" and made other comments indicating he doesn't necessarily view their relationship as permanent. Brad's remarks were made in an interview promoting his latest movie, The Curious Case of Benjamin Button.

She's so worried she's insisting they get married soon, sources tell The ENQUIRER.

And Angelina has good reason to be concerned, say top psychologists, who explain that Brad's "one-foot-out-the-door" mentality is exactly what destroyed his marriage to Jen.

In 2004 - when he was still married to Jen  - Brad told Oprah Winfrey: "There is so much pressure from day one to be with someone forever, and I'm not quite sure if it's really in our nature to be with one person for the rest of our lives."

After Brad moved on to new love with Angelina, his attitude remained the same.

"Any love involves loss, and that's the risk you take," he recently told the Los Angeles Times.

"The greater the love, the greater the loss. I certainly feel that now with the woman I'm with, and the children that I have. But whatever the course may be, this time together is extraordinary."

Dr. Gilda Carle - a relationship expert and author of How to Win When Your Mate Cheats - says Brad "appears not to be committed to the longevity of his relationship with Angelina and has the cavalier attitude that life is short - so when the going gets rough, I'll get going."

Angelina exploded when she read the interview and blasted Brad about his nonchalant attitude toward their relationship, said an insider.

"They got into a raging fight over the holidays because Angelina doesn't think Brad is committed," continued the insider. "She is furious over Brad's casual approach to their relationship - and especially over his habit of talking publicly about his fear of commitment.

"Angelina is actually starting to think Jen nailed it when she said Brad had a 'sensitivity chip' missing."

The feuding couple made up just before Christmas, but their relationship is  back skating on very thin ice despite public appearances.

"Angelina is starved for physical and emotional affection because of the demands of raising six kids," added the insider.

"There's no doubt Brad loves her and the kids - but Angelina wants to be certain his love is forever." 

As in legally married.