Mariah Carey might be keeping silent about the $2.5 million 17-carat engagement rock on her finger, but her new beau isn't. Actor Nick Cannon was overheard yesterday saying the pair are going to marry, reports the New York Post, during a follow-up visit to the New York jeweler where he purchased the bauble. "Maybe he's making payments on it," laughed the Post's source. Carey started sporting the ring last week.