Mariah Carey is giving fans some insight into her conversation with Rihanna after Carey signed her boob at a Christmas concert. Source: Justin Goff Photos PG/Bauer-Griffin The singer made an appearance on Jimmy Kimmel Live! on Thursday, July 24, where she opened up about the promise Rihanna made after Carey signed her boob at the final show of her Christmas Time tour at Brooklyn's Barclays Center last December. When she was asked by Fortune Feimster, who's guest hosting the show, if signing breasts were a common request from fans, Mariah admitted, "Not really.