We've been nostalgic for Mischa Barton since last week's decade anniversary of "The O.C." Unfortunately, the starlet has some bad news.
A source close to Barton confirms she and boyfriend Sebastian Knapp broke up. According to E! News, the pair's separation (pictured below in April) was amicable.
For now, Barton is focusing on film projects including "Beyond Justice" with Timothy Woodward Jr. and Vinnie Jones.
We feel for you, Marissa, er, Mischa.