Leighton Meester and her beau, Sebastian Stan, are taking the next step.

A source close to the starlet said the inseparable lovers are engaged – and they made the announcement on their “secret” Facebook pages.

“Gossip Girl” star Meester and Stan have been dating since they met on the set of the show last year, when Sand played a character who was featured in two early episodes.

Leighton Meester‘s rep had “no comment.”