Madonna is prepared to grind hard to promote man-candy Jesus Luz’s career. The pop superstar showed up to catch the tail end of her boyfriend’s DJ gig at the DVD release party of Matt Tyrnauer‘s “Valentino: The Last Emperor” on the 18th floor of the Standard Hotel. “She was grinding with a bunch of hot fashion guys while Luz spun,” says a spy. “She’s been tak ing a more active role in promoting him, so she stuck around for a bit and mingled before they left together (right).” Ma donna has already given her Brazilian boy-toy’s modeling ca reer a push, helping him land a juicy contract with Dolce & Gabbana, although her rep insists she’s “not at all involved in managing the career of Jesus Luz.” Also in attendance were Adrian Brody, Charlie Rose, Diane von Furstenberg, Martha Stewart, Marc Jacobs, Katie Lee — who was overheard discussing her new book of recipes in the elevator — and Brian Grazer and his former “culture czar” Brad Grossman.