Mr. Big is about to be a daddy. Sex and the City star Chris Noth and his girlfriend, actress Tara Wilson, are expecting their first child, a rep for the actor confirms to Usmagazine.com. "Chris and Tara are very happy and have always agreed to keep what is most personal in their lives private," Noth's rep says. A source tells Us that Wilson is five months along. "They live together and are very in love," the source adds. "Chris is very happy," Noel Ashman, Noth's co-partner of NYC hot spot The Plumm, told the New York Post, which first reported the news. Earlier this week, Noth stirred controversy by calling the Bush Administration the "biggest tragedy in the history of the United States."