Two words: Awe. Some. Gossip Girl stars Leighton Meester and Blake Lively have agreed to guest star on NBC's 30 Rock in November!

If you haven't seen that show before, we highly recommend it - and with the Gossip Girl gals set to appear, you're totally out of excuses.

According to EW's Michael Ausiello, the dynamic duo will play former high school classmates of Liz Lemon's (Tina Fey) in a flashback sequence that reveals an ironic truth about morally superior Liz: She was a Mean Girl!

The Gossip Girl-inspired flashback coincides with Liz Lemon's 20-year high school reunion, which means we're also going to meet the adult versions of the characters portrayed in the flashbacks by Meester and Lively.

Oh, and get this - 30 Rock is talking to none other than Blake's older sister, Robyn Lively, 36, about playing the latter part! Hilarious!

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