Mandy Moore and DJ A.M.: New Couple?
Moore, 22, and Goldstein, 33, have known each other for years, the source says, but started spending more time together after running into each other at a New Year's Eve party in Miami.
"It's really new. They're in the beginning stages of getting to know each other," says the source. "They're very into each other. It's very sweet."
Moore was spotted on New Year's Eve getting close to Valderrama, but since arriving back in Los Angeles has been keeping company with Goldstein.
She previously dated Scrubs star Zach Braff. They reportedly split last year, and in July she was spotted having a cozy lunch with another ex, tennis star Andy Roddick. (Roddick told PEOPLE in December that they were just friends: "We're cool.")
A rep for Goldstein, who previously dated Nicole Richie, has no comment. Moore's rep won't comment on her personal life.