Exclusive: Source: Leighton Meester "Still Friends" With Ex Despite Split

Leighton Meester is a single Gossip Girl once more.

A source close to the 24-year-old actress confirms to UsMagazine.com that she has broken up with actor Sebastian Stan, 26, her boyfriend since 2008.

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"They are still friends," the source tells Us. "It was amicable. They still talk all the time."

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Meester and Stan met -- and made out -- on the set of her show Gossip Girl, where Stan occasionally guest-stars as Carter Baizen.

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For Valentine's Day 2009, they enjoyed a couples' retreat in Jamaica with fellow Gossip Girl pair Jessica Szhor and Ed Westwick.  Last October, Meester gushed to Buzznet about a romantic gift -- a painting -- from Stan, whom she called her "best friend" and "boyfriend."

"He told the artist about me, my favorite colors and poetry and she painted a large very special abstract work I have hanging in my dining room," she said.