Nate Berkus has a new man in his life: Rachel Zoe’s old assistant, Jeremiah Brent. The two were spotted canoodling at Barneys on Madison Avenue Sunday evening. “They were kissing at the sunglass rack in the men’s section,” said a spy. Berkus and Brent, an interior designer who appeared on “The Rachel Zoe Project,” also took some loops around the skating rink in Central Park, according to photos on Twitter. Brent also supported Berkus at his Bergdorf signing of his book, “The Things That Matter.”