St. Vincent makes an appearance at the Valentine's Day party, and Blair has a big surprise waiting for Serena in this new clip from Monday's episode of Gossip Girl, entitled "Crazy Cupid Love."

Based on the producers' preview we posted earlier today, we have a pretty good idea what that surprise consists of. Whether Dan has any idea he's involved in this ruse is another story.

Or maybe we're wrong. What do you think Blair's surprise for her BFF might be?

Check out the scene from B's "simulation" Constance/St. Jude's party below:

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