Monday, we reported that Kelly Rutherford (Lily) is pregnant with her second child. But that's not the Gossip Girl baby buzz that has the fans talking.

As the promos for next Monday's episode make abundantly, clear, someone is harboring a secret. A huge secret. Even by Gossip Girl standards.

According to E! Online, it does indeed involve a baby.

The twists and turns just keep coming on the Upper East Side, and Monday's episode, "O Brother, Where Bart Thou?" is certainly no exception.

Inside sources have revealed that not only is next week's episode (about the aftermath of Bart Bass' accident) one of the most gripping episodes yet, it involves a jaw-dropping twist for one of the Gossip Girl gals - a pregnancy.

Yes, we will find out that one of the Upper East Side females we know and love is (gulp) with child. Now that certainly qualifies as a significant plot twist.

Any theories on this Gossip Girl development? Post them below!

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