Blair is welcoming a special guest in next episode of "Gossip Girl" as Prince Grimaldi is in town. Planning to miss a class to have a date with Hugo Becker's character, the Waldorf girl cannot tell her friends with whom she will be spending the night.
Also in "Petty in Pink", Blair and Dan's secret affair is in danger to be uncovered with Serena sending Charlie (guest star Kaylee DeFer) to go undercover Gossip Girl-style to determine why the twosome are spending so much time together.
With Nate's help, Raina decides to go on a search for her long-lost mother. Meanwhile, Chuck's hopes about his legacy are dashed with the reveal of devastating information from the past.
Blair's love story will get more complicated towards the season 4 finale as she will be caught in a love rectangle involving Dan, the prince and Chuck before she chooses the love of her life.
"Petty in Pink" will air Monday, April 25 at 9/8c on The CW. The last episode of this season will air three weeks later on May 16.