Clooney and Keibler at the 2013 Academy Awards (Getty Images)
The couple, who haven't been seen together since mid-March, have reportedly separated over Keibler's desire to have children.
"Stacy called it quits," a source close to the couple tells People. "She wants to have children and a family someday. She knows where George stands on that."
"They talked and they quietly stopped being a couple several weeks ago," the source continues, adding that Clooney, 52, and Keibler, 33, remain close. "They talk every day. They were friends before they started dating and they'll be friends after. It was a friendly [breakup]."
When reached for comment, a rep for Clooney replied, "George has never commented on his personal life and neither will I."
Omg! has reached out to a rep for Keibler as well but has not yet received a response.
Speculation about a breakup reached a crescendo during 4th of July weekend when Clooney was photographed without Keibler at his vacation home in Lake Como, Italy. Meanwhile, she posted a couple of photos from Malibu on her Instagram over the holiday, including one of herself with another guy (although it's unclear who he is).
Clooney at Lake Como on the 4th of July (Splash News)
Keibler's 4th of July post from Malibu (Instagram)
The last time the couple actually was seen together was on March 21 in Berlin, when Keibler was photographed visiting Clooney on the set of his upcoming film "The Monuments Men."
Clooney and Keibler in Berlin, March 2013 (Splash News)
The most telltale sign of trouble in recent months took place over Memorial Day weekend, when Clooney was photographed leaving a London club at 3 a.m., around the same time a former flame of his named Monika Jakisic was also exiting.
Clooney's rep issued a statement from the actor at the time saying, "The story is made up. I wasn't holding anybody's hand. Stop trying to sell magazines by creating scandal that isn't there." The strong denial spoke volumes, but, interestingly, contained no mention of Keibler.
That same weekend, Keibler was just a hop, skip, and a jump away, also in Europe. The former professional wrestler had a "zip slip" wardrobe malfunction in Monte Carloat the Formula One F1 Grand Prix event.
Keibler's been busy recently promoting her new game show, "Supermarket Superstar," which premieres July 22 on Lifetime, while Clooney has been continuing to shoot "The Monuments Men" in Europe, which he wrote, and is directing and starring in.
Below is a brief timeline of Keibler and Clooney's tumultuous 2013.
January 9: Clooney releases his sexy new ad for his Casamigos tequila with friend Rande Gerber. The ad also stars Keibler, along with Gerber's wife, Cindy Crawford.
January 13: Clooney and Keibler appear on the Golden Globes red carpet together, doing shots of his tequila with "omg! Insider."
February 24: Clooney and Keibler appear happy walking the Oscars red carpet together.
March 6: Us Weekly reports "the end is near" for Clooney and Keibler.
March 14: Split rumors head into overdrive. However, Keibler tweets a photo of herself jetting off to Berlin to visit her beau.
March 15: Date night! Keibler and Clooney are photographed leaving Berlin Royal Grill, where Matt Damon had joined them.
March 21: Keibler is spotted visiting Clooney on set in Berlin.
April: Clooney is seen around Berlin, while Keibler is spotted in Los Angeles.
May 1: Clooney is still in Berlin filming.
May 3: Keibler in seen in Barcelona.
May 6: Keibler stuns on the red carpet in a Rachel Roy dress at the Met Gala, but she's missing one key accessory — Clooney.
May 12: Clooney and Damon hang at his home in Lake Como, Italy.
May 23: Keibler continues to party it up at the Cannes Film Festival, and attends amfAR gala, sans Clooney.
May 23: Clooney enjoys some downtime in London, and is spotted dining at Nobu with friends.
May 25: Clooney is spotted out at a member's only club — Loulou's — in the Mayfair neighborhood of London until 3 a.m. Life & Style reports that Clooney held hands with ex-girlfriend, Croatian model Monika Jakisic. Clooney later strongly denies this, an odd move for the actor to make if things with Keibler were really fizzling: "The story is made up. I wasn't holding anybody's hand. Stop trying to sell magazines by creating scandal that isn’t there."
May 26: Keibler has a wardrobe malfunction in Monaco.
Weekend of June 8-9: Keibler hits the GoPro Mountain Games in Colorado, sharing a photo of herself being photobombed by a belly-flopping dog, while Clooney is in the U.K. filming "The Monuments Men," co-starring Matt Damon, Jean Dujardin, and Bill Murray.
- with additional reporting by Taryn Ryder
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