The actor got on one knee with a 12-carat diamond ring immediately after they left the Metropolitan Museum of Art Costume Gala, when they were chauffeured in a Rolls Royce to Times Square, according to the rep. Projected on a giant MTV jumbotron were the words, "Selita will you marry me?"

"They got engaged last night," Ebanks's agent, Chris Gay of Women Model Management told PEOPLE Tuesday. "He took her to Times Square last night and did it in the center of Times Square. Then they had a party after the Met Gala to celebrate. The two of them flew to L.A. late last night because both are working."

The couple celebrated at the New York nightclub Butter, with Cannon surprising Ebanks by flying in his mother, both her parents and best friends into town. As the couple made their way through the crowd holding hands, Ebanks was smiling from ear to ear. Upon coming up to one man, she exclaimed, "Nick! Have you met my brother?"

The couple left the party at 3 a.m. and caught a private plane back to L.A., where Cannon is working on his new film, American Son, the rep said.

Labels: Nick Cannon, Selita Ebanks