George Clooney and his fiancée, Amal Alamuddin, celebrated their engagement at an intimate yet star-studded party Sunday night at Cafe Habana in Malibu.

Alamuddin, who is an international human rights lawyer, was reportedly spotted wearing a green top, a black jacket and short pants, while the 53-year-old actor was photographed wearing a blue shirt and jeans. The couple was joined by the restaurant’s owner, Rande Gerber, and his supermodel wife, Cindy Crawford, and U2 frontman Bono.

"People got a show they didn't expect and other [restaurant patrons] said it was the best Mother's Day ever," a source told E! News, adding that the restaurant was packed for the Mother’s Day celebration.

“The Monuments Men” star and the British lawyer got engaged last month after a few months of dating. The couple is reportedly planning to tie the knot sometime in September. 

Clooney's father, Nicholas, confirmed the engagement, telling Daily News shortly after the news emerged: "It's true, and we're thrilled. We think Amal is a wonderful girl, and it's wonderful news. We think it will be a great marriage."

The couple was seen vacationing last week in Cabo San Lucas, Mexico. And, according to E! News, they had a romantic dinner and were joined by a group of friends at a downtown hotspot, Harbard. According to an eyewitness, the couple held hands throughout the night and laughed.

"You can tell these two are in love," the source told E! News.