updated 01/27/2011 AT 2:00 PM ET
•originally published 01/27/2011 AT 2:15 PM ET
Scarlett Johansson may have been Justin Long’s concert date to Wednesday’s Iron and Wine show in L.A. – but it was just a friendly outing.
“They re friends,” Johansson’s rep tells PEOPLE of the pair, who joined another couple for the indie rock show at the Wiltern in Los Angeles. “They’ve worked together [on He’s Just Not That Into You]. They re not dating.”
But they did seem to be having fun.
The two were described as being “flirty” in a “friendly” way during the evening. After the show, Johansson slipped backstage to hang out with the band’s singer, Samuel Beam.
“They’re just friends,” the source says. “They’ve known each other a long time.”
Reporting by ALEXIS CHIU, JENNIFER GARCIA and JESSICA HERNDON