Blair Waldorf have finally met her match in Seth Cohen!

Adam Brody has recently proposed to Leighton Meester -- and she said yes, a source told E! News.

Another source told Star magazine that the "Gossip Girl" star did not see the proposal coming -- and quickly, considering that they have only been dating for nine months.

"(S)he had no idea he would propose so soon! It was the surprise of her life and she's ecstatic!" the source says.

Wonderwall also reports that the couple celebrated their engagement with family and close friends at a party in Los Angeles last Nov. 10.

While news of engagement is yet to be confirmed by the couple or their reps, they have been spotted a number of times in separate occasions in New York and Los Angeles.

The two actors met on set of the indie movie "The Oranges" back in 2011, but it was not in Feb. that fans outed the relationship between the two.

Leighton and Adam have both dated a string of celebrities prior to their affair. She has dated "Gossip Girl" co-star Sebastian Stan, after which she became involved with "Remember the Haze" co-star Aaron Himelstein.

Adam, on the other hand, dated his "The OC" co-star Rachel Bilson for three years. In 2010, he was reportedly seeing screenwriter Lorene Scafaria.

But while the couple has been hush-hush about the details of their relationship, Leighton freely talks about her love life in general during a magazine shoot for Cosmopolitan. She says that unlike her character Blair Waldorf, she is not into bad guys like Chuck Bass, played by Ed Westwick.

"I think the term [bad boys] is stupid," Leighton says. "A guy who cheats on you or is not nice to you? What is that?"

She also admits of her reluctance to jump into the love boat, saying "I've never fallen in love right off the bat. I get scared to say I love you too soon because it means so much. It means you're not seeing an end to things."

She does, however, believe in romantic chemistry, the type where "(y)ou just really, really want to, like, stare at the person."