Leighton Meester is dating Adam Brody.

The couple - who co-starred in 2011 romantic-comedy movie 'The Oranges' - have reportedly been secretly seeing each other for several weeks, which comes after they used to ''hang out'' together while shooting the film.

An insider confirmed to Us Weekly: ''They were always close and friendly.''

The 26-year-old beauty - who is known for her role as Blair Waldorf in teen drama TV series 'Gossip Girl' - and the 33-year-old actor were spotted ''hugging and laughing'' as they took in art exhibitions at the Los Angeles County Museum of Art earlier this month.

One eyewitness, @CedricDiggory, wrote on Twitter: ''They were getting cuddly today at the LACMA apparently? Hugging & laughing. (sic)''

@tayeschbach19 tweeted: ''Just in the same museum exhibit with Adam Brody and leighton meester. Enough said. #lacelebsiting (sic)''

Leighton and Adam - who starred as Seth Cohen in US teen drama TV series 'The O.C.' for four years - also travelled to Bangkok together earlier this year where they were spotted at the Siam Kempinski Hotel in the Thai capital city.

Adam was recently linked to 34-year-old director Lorene Scafaria - who helmed Steve Carell and Keira Knightley's comedy-drama movie 'Seeking a Friend for the End of the World' - while Leighton has previously dated 'Austin Powers' actor Aaron Himelstein.