"Dancing with the Stars"' professional dancer Maksim Chmerkovskiy proposed to Karina Smirnoff on New Year's Eve. Now the two are posing for a date-night photo shoot for OK! Magazine -- and ET is behind the scenes.

"We are having fun," Maks tells ET. "We ate, laughed and drank a little, but then [the photographer] told us to stop."

The two dancers have known each other since they were children, but their romance is a new twist to their relationship. They only began dating a few months before becoming engaged. So now that they are back to work with new celebrity partners -- Maks is dancing with Denise Richards and Karina is partnered with Steve Wozniak -- does that add a little bit of jealousy to the competition?

Karina jokes, "Maks is extremely jealous of Steve. We have arguments about it every day."

"[Denise and I] are going to dance a sexy rumba, and people are going to talk," Maks says, "If we don't do a sexy rumba, they will say we did a bad rumba. So damned if you do, and damned if you don't."

Both professional dancers are rehearsing with their partners six to seven hours a day, so they have been too busy to firm up any wedding plans, but they are talking -- and disagreeing.

"He always tells me I am planning the wedding, but he tells me what to do, so I am planning it his way. We are negotiating now," says Karina, who tells ET she wants to get married at city hall and then have a honeymoon that lasts 12 months.

The issue of OK! Magazine featuring Maksim and Karina is on newsstands Friday, March 13.