A wild foursome sparked the interest of an A-List crowd celebrating Nas’ birthday Wednesday night. Jay-Z, Carmelo and La La Anthony, Ne-Yo, Common, Andre Harrell and Mos Def marked the rapper’s 38th at new hot spot Catch in the Meatpacking District. “While everyone was celebrating, a foursome was going on at the Gansevoort Hotel across the street,” a witness told Page Six. “Everyone turned their attention to the lucky guy who left the shades to his hotel room open while he was all over three other girls. The group sex was the talk of the party.” After midnight, Nas’ crowd headed upstairs to Jeremy Scott’s Belvedere Red after-party, where the hipster-fashion bash turned hip-hop. Bradley Cooper and Zoe Saldana, who are going into production on a new thriller “The Words,” were dining at Catch separately with friends and family but mingled together at Nas’ party. The rapper and “Avatar” star Saldana, there with her fiancé, Keith Britton, have many mutual friends from growing up in Queens.