After an unexpected sequence of events, Blair and the Prince went public on last night's Gossip Girl. At long last, our Queen B's dreams appear to be coming true.

Unless Serena jeopardizes it all by dredging up Blair's past.

That's what she'll do, according to the CW's episode synopsis for "The Princesses and the Frog." Is Serena the new Blair and Blair the new Serena? Looks like it.

Meanwhile, Charlie befriends Vanessa, who may or may not have a hidden agenda, and Nate is torn between his relationship with Raina and loyalty to Chuck.

Here's the first promo for the May 2 episode (more to come):

UPDATE: The extended version of the promo is live below ...

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.