A SNEAKY cheating scandal doomed Rich­ard Gere’s 11-year marriage to screen beauty Carey Lowell and ignited what’s sure to be an ugly $50 million divorce battle, sources tell The ENQUIRER.

In a bombshell exclusive, sources reveal how the 64-year-old “American Gigolo” star’s roving eye sparked numerous battles with his 52-year-old wife – and we discovered the shock­ing details of Gere’s disastrous attempt to bed one of Carey’s close pals.

“The final blow to the marriage came when a nasty fight erupted between Richard and Carey over his attempt to cheat with one of Carey’s friends,” an insider told The ENQUIRER.

“That was the ultimate slap in the face.

“After a screaming match, Carey told him, ‘It’s over!’ The woman that Richard wanted to bed was a gorgeous younger lady who does yoga with Carey.”

Gere got the surprise of his life when the woman not only told Carey about the actor com­ing onto her, but also informed the former “Law & Order” ac­tress about other females in their group he’s approached.

“That was the last straw for Carey,” revealed a close source.

“She broke down in tears and laid into Richard, screaming at him for being so disrespectful. She told him she wanted a divorce.

“Richard agreed they’d grown too far apart, but Carey’s heart was bro­ken by how easily he could walk away.”

The suave actor, who’s worth an estimated $50 million, wed the former Bond Girl in 2002. The couple, who own a luxurious bed-and-breakfast in Bedford, N.Y., have one child, 13-year-old son Homer.

Still stunning, Carey became frustrated with Hollywood and stopped acting in 2007. Both she and Richard are practicing Budd-hists and yoga enthusiasts.

As The ENQUIRER exclusive­ly reported in December 2012, the beauty blew her stack when Richard tried to cozy up to an at­tractive blonde at a restaurant in East Hampton, N.Y. – triggering a confrontation with the wom­an’s husband.

And just six months ago, in our March 18 issue, we reported how the notorious skirt-chaser infuriated his wife by rushing to comfort his “Unfaithful” co-star Diane Lane after she announced she was divorcing her husband Josh Brolin.

“Carey is seething that Richard was the first to rush in and help a damsel in distress,” a source told us at the time. “She knows he enjoys playing that role and believes he flirts with every vul­nerable woman he stumbles upon.”

Gere, who was married to supermodel Cindy Crawford from 1991 to 1995, also report­edly upset Carey because of a rumored affair with his “No Mer­cy” and “Final Analysis” co-star Kim Basinger, said the insider.

Although a representative for Gere denies their marriage crum­bled because of other women, the insider insists: “Carey knew it was time to leave when he started coming on to her friends. She’s steaming and could  easily take him to the cleaners.”