CAVALLI’S GOOD DEED: Though Roberto Cavalli has been busy opening a string of nightclubs — the first opened last Saturday in a renovated 15th century church in Florence — he took time Wednesday night to give back to a group of nearly 25 youngsters from the Little Sisters of the Assumption community center in East Harlem through a partnership with Free Arts NYC. The Italian designer, along with Free Arts board member and stylist Mary Alice Stephenson, spent two hours with the youngsters who were familiar with Cavalli’s work through his designs worn by the likes of Beyoncé, Christina Aguilera and Miley Cyrus. Cavalli supplied his sartorial guidance and his own fabrics to the children to help them make handmade scarves with various beaded and jewel adornments. He also gave them briefcases of art supplies from FAO Schwarz. “He was the most fashion Santa Claus I’ve ever seen,” said Stephenson of Cavalli.