Mandy Moore and DJ AM Call it Quits
"It was mutual," says the source, adding that the couple split about 10 days ago.
Word of the breakup was first reported Monday by the New York Post's Page Six.
A source told PEOPLE in January that Moore, 22, and Goldstein, 33, were "in the beginning stages" of dating. The pair had known each other for years but started spending more time together after running into each other at a New Year's Eve party in Miami, the source added.
When they returned home to Los Angeles, they started dating, and they were spotted later in January at the Sundance Film Festival, where Moore was promoting Dedication and Goldstein was a party DJ.
Just one month into their relationship, Moore told PEOPLE at the premiere of her film Because I Said So, "I don't enjoy dating in the public eye. I don't even really enjoy dating."
Asked if she was seeing Goldstein, she smiled, shrugged and said, "I don't know" – though they were later seen kissing at the after-party.
Moore's rep said she doesn't comment on her clients' personal lives. A rep for Goldstein could not immediately be reached.