George Clooney is reportedly engaged to his girlfriend, human rights lawyer Amal Alamuddin.

George Clooney, Amal Alamuddin Engaged?

Clooney, 52, and Alamuddin, 36, went out on a double date Thursday night at Nobu in Malibu, Calif., with Cindy Crawford and her husband Rande Gerber. During the outing, fellow diners spotted Alamuddin sporting a diamond on her left ring finger, which sparked the engagement rumors.

“George and Amal are trying to keep things very low-key but they also aren't really trying to hide this, it doesn't seem,” an insider told People magazine. “I think it's like they want the people they love to know that this is real, that they plan on being together forever."

The source added that the two haven't been engaged for long and don't have wedding plans in the works yet.

Stan Rosenfield, Clooney’s publicist, declined to confirm the nuptial news, releasing a statement, which simply reads, “I don’t comment on my client’s personal life.”

Clooney and Alamuddin were first linked in October of last year. Since then, the two have been photographed together around the world, including in New York, London, Tanzania and Seychelles.

Clooney was previously married to actress Talia Balsam from 1989 to 1993. Since then, the actor has been in a number of long-term relationships, most recently with former WWE star Stacy Keibler. Keibler is now married and expecting her first child with businessman Jared Pobre.

– Chelsea Regan