The little ones' musically inclined parents give fans a peek into their spacious caramel-and-white-gingham-wallpapered Manhattan nursery, in a 20/20 special with Barbara Walters airing Friday at 10 p.m. on ABC.
Carey and Cannon are all smiles now, but the process – including a miscarriage – leading up to the April birth of their children was not always easy for the couple.
"I don't think I understood the enormity or the magnitude of what it really does to your body," Carey, who admits to fertility treatments, says in a clip from the special. "Like it's not just, oh you don't look pretty and you have a bump."
Aside from all the baby talk, Carey admits her adoring hubby isn't always on his best behavior.
"When he's nice, he's the best guy in the world," she says. "You know, he's a man, Barbara. Let's call it what it is."
But Cannon assures his wife she can "absolutely" trust him all the time, and she goes on to say she's "happy to be in love."