From PEOPLE Magazine Click to enlarge
Anyone hoping to samba with sexy Dancing with the Stars pros Karina Smirnoff or Maksim Chmerkovskiy is out of luck: Their dance cards are now officially full. On New Year's Eve Day at the Wynn Hotel in Las Vegas, Chmerkovskiy, 29, popped the question to Smirnoff, two days before she turned 31. "I wanted her memory of 2008 to be pleasant and positive," he says of his girlfriend of the past four months.

Actually, Smirnoff confesses, the big moment was not only memorable but comical. Chmerkovskiy, known for his macho persona on DWTS, lost all swagger when he presented Smirnoff with a three-carat Harry Winston square-cut-diamond-and-platinum engagement ring tucked inside a Louis Vuitton bag. "He got so nervous. He had difficulty forming sentences, which was so cute," Smirnoff says, giggling.

The pair—who have not set a wedding date—have known each other for 14 years as competitive ballroom dancers living in the New York City area. But after other relationships—including Smirnoff's high-profile romance with former DWTS celeb partner Mario Lopez—ended, the old friends began feeling more than platonic toward each other. In September, while having a casual dinner together, "we started talking and looking at each other completely differently," Smirnoff says. Adds Chmerkovskiy: "I'm not really sure how it happened, but it makes sense. I'm in love and so is she." Even the whirlwind courtship hasn't caused the couple to miss a step. "It's all good," says Chmerkovskiy. "Everything is beautiful."