Watch : Dancing With the Stars' Mark Ballas Calls Out BFF Derek Hough for Being "Messy House Guest"Mother knows best. At least that's what Dancing With the Stars: The Next Pro's Shirley Ballas was trying to convey to son Mark Ballas during a tense exchange on the ABC reality competition series' Aug. 10 episode. When it came time for partners Selena Hamilton and Erik Linder to face the judges after their contemporary routine, which featured a "moment of stillness" as their "wow" moment, Shirley and Mark were fiercely divided over the performance. Selena attempted to explain that "sometimes the 'wow' is in the silence," but the 65-year-old wasn't buying it. "In my experience," Shirley replied, "a silent moment doesn’t mean to just stand still."