The couple - who married in April 2008 - are believed to be expecting their first baby and though the rapper-and-presenter refused to be drawn on the speculation, he admits he and the singer would love to have a child of their own. He said: "I`ve never really thought about adopting. That`s never really come up. But marriage, you want to have a family, that`s one of the reasons to get married. When the timing is right." Nick also claims he hasn`t "thought about" what would be the most exciting aspect of fatherhood. He added to America`s OK! magazine: "What would excite me? I don`t know. Those are deep questions. I haven`t thought about those questions yet." The 29-year-old star has also promised fans that he and Mariah will reveal their baby news themselves, rather than allow friends to tell people. He said: "If and when my wife is ready to make any announcements about private matters she will do it personally." A source claimed that Mariah - who recently pulled out of a movie on medical grounds - is pregnant but trying to keep the news under wraps. The insider said: "They`re both very excited and very happy. "Mariah and Nick want to keep the pregnancy quiet as long as they can."