Jennifer Lopez's ex-husband says she is a "diva".The singer-and-actress was married to Cris Judd for nine months in 2001 and the dancer admits she wasn't always easy to work with.When asked who was the biggest diva he's worked with, Cris said: "The most respected one would have to be Diana Ross. It was a pleasure to work with her and we all called her Miss Ross. "But, of course, Jennifer was [a diva]! She's an amazing performer and a confident professional. She's always striving to be better. You have to respect that."Despite their short-lived union, Cris insists he and the former 'American Idol' judge are still on "good terms" and have an amicable relationship.He said: "I was doing a tribute for Michael Jackson at MTV and I saw her in the audience. We kind of waved at each other, and that was about it. The things that happened between us... It didn't work out, but it was amicable. We left on good terms."Cris previously worked with Michael, the late 'King of Pop' and credits the 'Thriller' hitmaker with making his dancing better.He added to new! magazine: "He made you become a better dancer just by walking in the room. He never demanded it from you, but it was expected of you to be the best you could be. You automatically think, 'I have to step up.' All I wanted to do was make, him proud."