Mischa Barton's ex-beau Cisco Adler is dating model and publishing heiress Lydia Hearst-Shaw, PEOPLE reports.

Adler, 29, the lead singer for Whitestarr accompanied Hearst-Shaw, 23, to The Cinema Society's screening of We Own the Night in New York on Oct. 9.

They were also seen the next night kissing in a private booth at New York’s hot nightclub The Box, and again together Thursday at the club Tenjune, where Adler was a guest DJ.

"It's true that Cisco and Lydia have been seen together in public recently," says Hearst-Shaw's publicist Alan Rish. "But I don't think this is serious. It is a very new relationship."