Brad Pitt and Angelina Jolie are reportedly headed for a split, but why?

Although the couple has allegedly both strayed from their marriage, reports claim it is Pitt's relatinoship with his Allied co-star, Marion Cotillard, which pushed them over the edge.

“She must feel like a breath of fresh air to him,” an insider told OK! Magazine of Cotillard and Pitt, via a Hollywood Life report last week.

According to the report, Jolie, who has been sporting what appears to be substantial weight loss in recent months, has been suffering from "many health problems," and while she has allegedly strayed from her marriage, as well, that doesn't mean she wouldn't be irate to find evidence of an affair between Pitt and Cotillard.

“She would be furious if Brad and Marion were sleeping together,” the source said. “It’s sad because they do still really care about each other, but it’s looking like the only way out of the jealousy and misery is a divorce.”

“For a while, the excitement of getting married masked their troubles,” a Brangelina insider continued to OK! magazine, via a second Hollywood Life report, “but lately, they’ve been having explosive fights. Neither of them is sure that they can or should, hang on anymore.”

Jolie “barely eats, she guzzles wine every night and she smokes constantly,” the insider said. “Brad’s just exhausted from spending so much energy trying to get her to take better care of herself. It’s been hard to watch the woman he loves waste away.”

Another report also spoke of a betrayal.

“Angie and Brad have had some serious arguments, and she told him she feels betrayed by him,” a source told Life & Style magazine, according to a report by the International Business Times on Saturday. “Recently, Angie became so enraged when Brad was talking about how great Lizzy was, she threw him out of their bedroom.”

Jolie also gets upset, understandably, whenever Pitt “gushes about how cute Marion’s accent is or talks about what a great actress she is,” the source said. "Angie is hoping their marriage can be saved, but she’s going to be gripped by fear the entire time [Brad is filming].”

Tags: Brad Pitt Angelina Jolie