BEAK TWEAK Blake Lively, before (l.) and after (r.)
Hey Upper East Siders! Gossip Girl here with a pop quiz: Which cast member had a bit of discreet work done on her nose before the show started filming?

That would be Blake Lively, the soignée blonde who plays reformed bad girl Serena van der Woodsen on the hit CW show, which chronicles the debauched lives of a coterie of attractive, white New York City prep school kids. (It's a hit in terms of "buzz," if not ratings.)

According to a well-placed source, Lively, 20, had the nose job after filming wrapped on 2006's Accepted. The source confirms that the California native underwent rhinoplasty and then signed on as a cast member, but that the two events were unrelated.

Multiple calls and emails to the actresses' publicists were not returned by the time of this posting, though the before-and-after photos of Lively seem to speak for themselves (the new nose is thinner, more streamlined, and decidedly cuter, in our totally non-medical opinion). On a side note: Does frenemy Blair really get pregnant in tomorrow's episode?!

Before (l.), after (r.)