George Clooney Turns 56 -- See His Hilarious Birthday Greetings and Insane Cake From Wife Amal!

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George Clooney had a birthday to remember.

The handsome actor and father-to-be turned 56 on Saturday, and his good pals took to social media to greet him. Clooney's close friend and Casamigos business partner Rande Gerber set the tone, ribbing him by sharing a throwback pic of the actor giving his best modeling pose.

"The modeling thing may not have worked out, but @casamigos sure did," Gerber joked. "Happy Birthday George!"

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Gerber wasn't the only friend of Clooney to share priceless throwbacks. Salma Hayek tweeted out an amazing photo of the two of them alongside Will Smith.

"Happy Birthday George! Feliz Cumpleaños Jorge! #georgeclooney," she wrote.

Gerber's wife, supermodel Cindy Crawford, also showed her affection for Clooney, sharing a cute photo of him with her and her husband.

"Happy birthday to one of the classiest guys we know!" she wrote.

But nothing was more impressive than Clooney's wife Amal's birthday cake for both her husband and 55-year-old Gerber, who celebrated his own birthday on April 27. The human rights lawyer, who's currently pregnant with twins, got them a Casamigos cake complete with cutouts of both them. A source tells ET Gerber and Crawford flew to London to surprise Clooney for his birthday, and Amal had an elaborate birthday cake made replicating the Casamigos tequila bar from Clooney and Gerber's houses in Mexico.

"Amal set it all up and Rande and Cindy surprised George when he got home," the source says. "He was totally surprised."

Gerber Instagrammed a pic of the epic cake on Monday. "Celebrating our Birthdays @casamigos style," Gerber wrote. "Thanks for the cool cake Amal. #houseoffriends."

Crawford also Instagrammed a funny photo of George third-wheeling her and her hubby in England.

"We can always count on him for the photobomb," she joked.

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Earlier this month, George and Amal donated $10,000 to Camp Cocker Rescue, an animal rescue organization, so that they can look after nine dogs they took in from a backyard breeder.

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-- Reporting by Kayley Stumpe