Mariah Carey is Pregnant With Twins

When Mariah Carey and Nick Cannon welcome their twin babies later this year, the new arrivals will be a son and a daughter, a source close to the couple confirms to UsMagazine.com.

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The insider explains how the pair found out: "They didn't want to know, but when they went to the doctor they wanted to make sure the babies were healthy, and then asked."

And now? "They are so excited! They are busy decorating the nurseries [in their L.A. and NYC homes] and using neutral colors now."

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Adds the source: "Those kids will have everything. Mariah and Nick are ecstatic. One of each! It's a dream come true."

Cannon, 30, confirmed in December that wife Carey, 40, was carrying twins (They first broke the news to President Barack Obama and First Lady Michelle Obama at a holiday event in Washington, D.C.)

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The first-time parents opened up to Us Weekly in November about their struggle to conceive following a heartbreaking miscarriage. "We definitely cried" upon learning of her successful pregnancy, Cannon told Us. "We still cry all the time. It's an emotional journey."