By Lisa Ingrassia
December 21, 2009 12:00 PM

By the time their third anniversary came around this September, Katie Couric and Brooks Perlin had gotten almost every jitter-inducing “first” out of the way: Couric, 52, had met her man’s family, vacationed with him in Mexico and even introduced him to her daughters Ellie, 18, and Carrie, 13. The one thing the CBS Evening News anchor hadn’t done was debut him as her date to an official event—until now.

On Nov. 24, Perlin, 35, accompanied Couric to a White House state dinner, and just two weeks later, the couple returned to Washington for the Kennedy Center Honors, where they struck their first pose together for photographers. “They took their time walking down the carpet,” says a fellow guest. “Katie was smiling a lot and in a very good mood. They never left each other’s side.” Those who know the couple expect Perlin, a former hedge-fund partner turned entrepreneur (who also regularly competes in triathlons), will continue to make good use of his tux. “They’re serious,” says a friend of Couric’s. “Brooks seems perfect for her. They make one another really happy.”