As Serena begins to be suspicious of Blair and Dan's intense meeting, the couple might be exposed when making out.
Things are getting complicated between Blair and Dan in the upcoming "Gossip Girl". As Serena is getting suspicious of the nature of relationship between the couple, she enlists Charlie to go undercover Gossip Girl-style to determine why Dan and Blair are spending so much time together, and what role an unexpected visitor is playing in their lives.
Meanwhile, with Nate's help, Raina decides to go on a search for her long-lost mother. Chuck's hopes about his legacy are dashed with the reveal of devastating information from the past.
By the end of season 4, Blair will choose the love of her life. But before that, it has been hinted that Leighton Meester's character will be caught in a love rectangle with Chuck, Dan, and Prince Grimaldi.
"Petty in Pink" will air Monday, April 25 on The CW. After that, there will be only two more episodes left before the season finale on May 16.