"I was up for it to a certain degree, but then at the same time, I might not even do that. We might just keep it private. We'll see what's up."
Carter and Kitt haven't set a wedding date, but he says they're thinking about "early next year."
The couple co-star in a series of fitness webisodes called "Kit Fitt." Carter is also busy recording a new album with the Backstreet Boys, due out later this year. He says the band is "90 percent done" with the album.
Carter says the Backstreet Boys have recorded a song with longtime collaborator and mega-hit maker Max Martin, who produced the boy band's hits including "I Want It That Way," "Quit Playing Games (With My Heart)" and "Everybody (Backstreet's Back)."
"It's a smash," he says of the new track. "A beautiful song."
Carter says he's also written three screenplays, including a horror film in which he'd play a villain.
"We're shopping them now to big studios in Hollywood," he says.
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