The couple - who are expecting twins in April - have revealed while they won't be naming their offspring anything too "crazy", they want to give them tags that will set them apart from the crowd.
Speaking of the impending new arrivals, Nick, 30, said: "We're building nurseries in both Los Angeles and New York. They won't be getting crazy names like Carburetor or something. But they're definitely unique."
The actor-and-comedian - who married the 40-year-old singer in 2008 - also explained Mariah isn't afraid of pandering to her pregnancy cravings, but he often ends up finishing off her dishes as by the time they have been cooked she usually isn't in the mood for food anymore.
He added to People magazine: "Last night we had smothered pork chops, collard greens, red beans and rice and a pecan pie with homemade whipped cream.
"She cooks it, tastes it, but instead of laying up and eating it, I end up eating it. I think she craves it, but once she cooks it and smells it then the cravings go away."