Nicole Kidman and Keith Urban, at the Kuwait-America Foundation dinner. (Vicky Pombo)

It’s one thing for a Hollywood couple to act lovely-dovey on the red carpet, another to see them together when they think no one is watching.

By that standard, it looks like the six-year marriage of Oscar-winning actress Nicole Kidman and county star Keith Urban is a happy one. The two Aussies, 44, sat side by side at Sunday’s Kuwait-America Foundation gala where they shared smiles and whispers. Urban rested his hand on his wife’s back as they sat through the inevitable D.C. dinner speeches. Kidman flew in from L.A., Urban from Nashville, and the two mingled hand-in-hand after a receiving line and posed for photos with fans in the pre-dinner reception.

Kidman received the night’s humanitarian award for her work as a goodwill ambassador of the United Nation’s UN Women, accepting “on behalf of a rather large group of people — the world of women,” she said. “There’s no limit to what women can achieve when they’re given the opportunity.”

Lynda Carter taking a turn on the mic during Sunday’s dinner. (Vicky Pombo)

The Al-Sabahs assembled their annual A-list mix of power and glamour: David Petraeus, Jacob Lew, Tom Donilon, Sam Alito, John Kerry and Scott Brown, John Dingell, David Gregory, a dozen ambassadors and top corporate donors who raised $2 million for Women’s World Banking and micro-credit loans in rural Jordan.

After dinner, a little cabaret show by Lynda Carter: “Let’s Stay Together,” “Crazy Little Thing Called Love,” and “Chattanooga Choo-Choo.”

The crowd seemed to love her — especially Urban, tapping his head and foot to the music. He whooped when Carter introduced her back-up singers from Nashville. Had fun?

“I did,” Urban told us with a broad smile. “Where else would you get to hear Wonder Woman sing?”

Read earlier: Bill Clinton talks (and talks) at Kuwait-America Foundation gala, 3/7/11