MARK BALLAS AND MELISSA JOAN HART PREP FOR UPCOMING DANCING WITH THE STARS

Dancing With The Stars professional dancer Mark Ballas has revealed a secret -- he used to love to watch his new partner for this season when she was in Clarissa Explains It All. Melissa Joan Hart played the part of Clarissa Darling before achieving even greater fame on the hit comedy, Sabrina The Teenage Witch.

"I would tell my mom not to talk to me when it was on," confided Ballas to digitalspy.

Ballas has achieved his own fame as a professional dancer on Dancing With The Stars -- and last year won the dance competition trophy with Olympic gymnast Shawn Johnson.

Hart is "doing pretty well so far," confided Ballas. "She has a tendency to kind of want to do all the hard stuff now. We've got to build up to it."

For her part, Hart has admitted to realitytv that she is nervous -- that she hopes that she will not throw up from a case of nerves. She also said, "People keep saying, 'Don't do it unless you're going to win.' It all depends on what I'm able to pull off and what the other competition is like. I think Donny (Osmond) is the most popular of the group, for sure. And I think he's going to get the popular vote. I just hope he can't dance very well."