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Mariah Carey insists she isn't pregnant, but she and husband Nick Cannon are ready when the big day comes.

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They've already picked out their baby names -- but she won't reveal them."We have to keep the name secret because if we told everybody, then somebody might use it and then we have to change it, and then it wouldn't be as good," the Precious star, 39, said Tuesday on SIRIUS XM's Morning Mash Up. "We picked these names out a long time ago."

Listen to Mariah and Nick's interview on the Morning Mash Up!Cannon, 28, suggested a little one could be on the way.

See funny vacation photos of Mariah and Nick!

Asked for their secret to a happy marriage, her husband of one year replied, "Lots of sex!"

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Carey agreed that, "of course," sex is vital to their relationship, but "I'm shy. I don't say things like that. That's where he comes in."