Less than a year after Us Weekly broke news of their relationship, Leighton Meester and Adam Brody are indeed engaged, sources confirm Credit: Henry S. Dziekan III/WireImage.com

It's the ultimate Gossip Girl-O.C. crossover event! After less than a year of dating, Leighton Meester and Adam Brody are engaged to be married, a source confirms to Us Weekly. Wonderwall was first to break the news of the couple's unexpected wedding news.

Just last February, Us exclusively broke news that the Gossip Girl actress, 27, was dating the O.C. actor, 33. The pair (whose breakout TV shows were both created by Josh Schwartz) worked together on the 2011 film The Oranges and began "hanging out" in early 2013. It will be the first marriage for both. Before Brody, Meester dated actor Aaron Himelstein before calling things off during the 2012 holiday season. Brody, meanwhile, squired director and screenwriter Lorene Scafaria back in 2010.

The resolutely private couple (who were "always close and friendly" a pal told Us) have rarely commented on their relationship, but have made a small handful of affectionate, low-key appearances together in and around Hollywood over the past year. They'll also be working together again in the upcoming comedy Life Partners.

"I love love. It's the most intriguing universally understood emotion, and it comes in so many forms: family love, love of friends," Meester told Lucky magazine back in 2012. "I fall in love with everybody all the time."