'Dancing with the Stars'' Joanna Krupa & Derek Hough Reveal Their Guilty Pleasures!

Joanna Krupa and her professional partner Derek Hough go one-on-one -- only for ET! The partners have a good time because they make each other laugh, so when ET asks them to interview each other, the good times roll!

When Joanna asks, "What is the best thing about dancing with me?," Derek responds, "Your determination and your good work ethic. But most importantly, you are a really great person. It is like coming to work with one of my buddies. And you make me laugh when you laugh because your laugh is so contagious."

Joanna reveals that her nickname for Derek is goofball, "because that is what you are. You are just a fun goofball."