Mariah Carey’s ex husband Tommy Mottola is opening up about mentoring his ex-wife while he was a music executive and reveals that "obsessive” behaviour was necessary to make her the star that she is today. In an interview with the Today show’s Matt Lauer, Mottola responded to a passage from his new book Hitmaker: The Man and His Music, where -- among many other topics -- he addresses his "controlling” nature while nurturing Carey’s musical talent. "Well I think that anyone that is successful becomes obsessive with what they are trying to succeed at,” he tells Lauer. In the book, the former Sony Music Entertainment executive writes, "If it seemed like I was controlling let me apologize...” He then tells Lauer he thinks it "will be the first time” that his wife of five years will get such an apology for his past actions. Concerning his relationship with the singer -- who is 21 years his junior -- Mottola said he recognized now that it was a mistake at the time. "It was absolutely wrong and inappropriate for me to become involved with Mariah, and I’m not saying this because there was a generation gap, I should [have] listened to the piercing voice of my shrink and maintained my distance.”Agencies