Brooklyn Decker and Andy Roddick's Costa Rican honeymoon may have ended, but the happy couple are still enjoying their newlywed phase.

Being married "is great. It's amazing," Decker, 21, told PEOPLE at the Costume Institute Gala Monday night at New York's Metropolitan Musuem of Art. Still, she adds, life after tying the knot on April 17 with tennis champ Roddick, 26, "feels the same. It's the same as being engaged, it's the same as dating."

The Sports Illustrated swimsuit model, who was escorted to the fete by designer Derek Lam, admits she has had at least one disagreement with her new hubby: What to wear to the Met. "He told me not to wear pants," Decker said, glancing down at her sequined Derek Lam pantsuit with a laugh. "But I wore them anyway. It's cold! I wanted to be comfortable but he said, 'You can't wear pants. It's the Met!' "

The New York gala was certainly a change of scenery after the couple's intimate honeymoon in Costa Rica, following their Austin wedding. "It was quiet and lovely and nice that we got to be away from the madness of the wedding," says Decker. "So it was good. It was wonderful."

And though the pair didn't try out their surf skills in Costa Rica, they did hit the cloud forests for an eco-tour. "We did the zip lines," she says. "It was great, it was lovely. We had a good time."