Gossip Girl - Season 1 - Eps 13: The Thin Line Between Chuck and Nate
Gossip Girl reports that Serena van der Woodsen was seen buying pregnancy tests. Of course, on the Upper East Side, the truth is often even juicier and more scandalous than the gossip. Nate finds out about Blair and Chuck's affair. And when everyone else finds out what happened Blair's life comes crashing down. Meanwhile, Dan struggles to tell Serena those three special words.
About Gossip Girl

Title: Gossip Girl
First Air Date: 2007-09-19
Last Air Date: 2012-12-17
Status: Ended
Rating: 8.202/10 (from 2159 votes)
Language: EN
Seasons: 7
Total Episodes: 121
Network: The CW
Genres: Drama, Mystery
Production Companies: Warner Bros. Television, Alloy Entertainment, Fake Empire Productions, CBS Studios
Synopsis
An exclusive group of privileged teens from a posh prep school on Manhattan's Upper East Side whose lives revolve around the blog of the all-knowing albeit ultra-secretive Gossip Girl.
Cast

Blake Lively
Serena van der Woodsen

Leighton Meester
Blair Waldorf

Penn Badgley
Dan Humphrey

Chace Crawford
Nate Archibald

Ed Westwick
Chuck Bass

Kaylee DeFer
Ivy Dickens

Kelly Rutherford
Lily van der Woodsen

Matthew Settle
Rufus Humphrey