By Tzvi Machlin For the third NCAA Tournament in a row, Kelvin Sampson and the Houston Cougars are heading to the Sweet 16. But unlike the last two times, Sampson was in an unusually celebratory mood. Upon joining his team in the locker room, the 66-year-old Cougars head coach took his shirt off and started dancing with his players. Some of them even spilled some water on Sampson as part of the celebration. But apparently Sampson wasn’t aware that he was being filmed while he was dancing. When his players were asked questions about it in their post-game press conference, Sampson seemed shocked…