Gossip Girl Season 2 Episode 24 : Valley Girls
In a flashback to the 80s, 17-year-old Lily Rhodes (Brittany Snow) gets kicked out of boarding school and runs away to Los Angeles, reconnecting with her parents, Rick (Andrew McCarthy) and Cece (Cynthia Watros), and sister, Carol (Krysten Ritter). Back in present day, Blair and Nate attend prom together, but the evening doesn't turn out exactly as planned and Chuck and Serena have a little something to do with that. Serena and Lily don't see eye-to-eye over Serena's recent run-in with the law. No Doubt performs in the flashbacks as an 80s band called "Snowed Out."