On October 30, a rep for Ryan Phillippe and Reese Witherspoon, 30, released a statement announcing the couple’s separation. What wasn’t mentioned: The fact that Phillippe, 32, has recently grown close to Abbie Cornish, 24, his Australian costar in the indie film Stop Loss; according to an insider, during a shoot in August, Texas, from August to late October, the two had a fling. (“It’s not true,” Cornish’s rep said. “They are costars and that is it.” Reps for Phillippe and Witherspoon had no comment.)

On October 10, local Lauren Scott witnessed Phillippe and a blonde, who fit Cornish’s description, kissing at sushi restaurant Kenichi. “I was pretty shocked that he would blatantly cheat on Reese in public,” Scott told US. Other sources say things fell apart two weeks ago, hours after Ryan’s New York premiere of "Flags of Our Fathers," when Witherspoon found incriminating e-mails on her hubby’s BlackBerry.

Witherspoon was alerted to pictures of Phillippe with Cornish, says a source. When she confronted him about the relationship, “Ryan admitted it was true and said, ‘We just need to end this.’ Reese literally had no choice.”

It’s sad to see these two split.

Although Reese Witherspoon and Ryan Phillipe are keeping their divorce civil, the rumors are flying. Here’s more:

Did Reese Witherspoon dump her husband because he fell in love with his beautiful co-star?

The ENQUIRER has uncovered a shocking scandal behind the breakup and learned exclusively that Reese ended her marriage after she found secret messages that husband Ryan Phillippe sent to another woman on his BlackBerry, say sources.

The ENQUIRER has also learned that Ryan became EXTREMELY close to Abbie Cornish, his beautiful Australian co-star on a recently filmed movie with the working title "Stop Loss."

In fact, after the last day of filming in Austin, Texas, Ryan and Abbie had a cozy dinner alone at Kenichi, an Asian restaurant.

"They came into the restaurant a month ago, both casually dressed in warm-up outfits," an eyewitness told The ENQUIRER. "They asked for the restaurant staff to pull curtains around their table, so no one could see them." But, according to one unconfirmed posting on an internet blog, a diner could see around the partition and claimed to watch them making out.

"We sat two tables away from Phillippe and an extremely attractive blonde (not Reese)," a blogger wrote on a Web site called "Pink is the new Blog." "The couple had a partition placed around their table soon after they arrived, but we could still see their legs intertwined under the table.

"As we left, we could see them clearly making out behind the partition" said the blogger.

Reese, 30, and Ryan, 32, have admitted to attending marriage counseling. Sources now tell The ENQUIRER that when Reese found apparent email proof of Ryan cheating it finally convinced her to end the troubled relationship.

"Reese is heartbroken," a source told The ENQUIRER.

Reese discovered Ryan’s messages when she accompanied him to New York for the premiere of his movie "Flags of Our Fathers" on Oct. 16.

At the premiere the couple smiled and posed for photos together, "but when they got back to the hotel, Reese found Ryan’s BlackBerry, which he’d carelessly left in the bathroom – and she read it," said the source.

"Ryan was caught red-handed. All he could say was he didn’t mean what he’d written to the other woman."

Ryan went to Morocco to finish filming "Stop Loss" and hoped Reese would cool off while he was gone.

But when he got home to their Brentwood, CA., mansion in late October, he was no longer welcome. The marriage was over and Reese kicked him out.

Before announcing the split, Reese contacted Los Angeles celebrity divorce attorney Robert Kaufman, who has represented Jennifer Aniston and Lisa Marie Presley.

Ryan and Reese – who’s now Hollywood’s highest paid actress after finalizing a $29-million deal for her next film – will now have to determine custody of their two children, 7-year-old Ava and Deacon, 3.

Earlier this month there were reports that Reese and Ryan were feuding at the Flags of Our Father’s premiere, and now this.

Reese Witherspoon and Ryan Phillippe have separated. The couple’s rep released a statement Monday morning that says "We are saddened to announce that Reese & Ryan have decided to formally separate. They remain committed to their family and we ask that you please respect their privacy and the safety of their children at this time."

Sources say Witherspoon has contacted celebrity divorce lawyer Robert Kaufman, who has represented Jennifer Aniston, Roseanne and Lisa Marie Presley.

Sources also say Witherspoon spoke with Kaufman about divorcing Ryan Phillippe, her husband of seven years. The couple has two children. They met at Witherspoon’s 21st birthday party.

As for why Witherspoon contacted Kaufman, sources say it was not triggered by one event. Rather, one connected source says it was "cumulative."

Divorce papers have not yet been filed.

No pre-nup, and Reese makes 20 times more money. Next we’ll hear Reese say Ryan hit her. Good luck with that.

When I first saw the pictures of Reese Witherspoon and Ryan Phillipe at the Flags of our Fathers premiere, I thought Reese was there to support her man. Reese makes more money than Ryan, so he could use some support to help him land more roles, and increase his asking price. I have no idea what the problem was, but here’s what a photog said who was there:

Now I am not one to gossip, but I hear the two sweethearts exchanged words upstairs, with Reese telling Ryan, "I don’t know what you mean by saying I am embarrassing you, how could you say I am embarrassing you?" Then the partygoer, who was standing close to me while recounting the story to a friend on the phone, said that Ryan stormed back into the room with the bar and Reese went into the bathroom. About 15 minutes after this incident, they exited the hotel where the party was held. She walked ahead of him with a smirked, he looked like he just sucked on a lemon.

Reese Witherspoon shows her support for husband Ryan Phillippe during a special New York screening of his film, the Clint Eastwood directed Flags of Our Fathers, on Monday. Looks like a great movie.