Chris Brown and Drake's nightclub brawl started brewing weeks ago -- as a Twitter war over Rihanna!! That's just one juicy detail we got straight from club insiders ... who saw how it all went down. Plus, "Cake Boss" Buddy Valastro calls in to offer a mea culpa for his transgender prank gone wrong -- and presidential politics with Ice-T. He says Prez. Obama couldn't have won the White House without 25 years of hip-hop ... but Harv disagrees. Challenge!