Forget about work, these designers "just want to have fun"! 

In an exclusive preview of the Project Runway show to be aired on Bravo on Thursday, December 9th, mentor Christian Siriano introduced two amazing celebrity guests to the designers: Cyndi Lauper and last season's champion Geoffrey Mac. The 19th season contestants could not contain their shock! 

"I don't have your model right now, but I have a special surprise," Christian teased when Geoffrey and Cyndi walked into the studio with their heads high. Cyndi's short haircut with pink stripes is particularly fashionable. 

After seeing these two stars, all the contestants' jaws (of course!) fell off. "Cyndi, the only one," designer Zayden gushed in a separate confession, "and Geoffrey, the winner of Project Runway, came in and we were all shocked like stars." 

Christian called the Grammy, Emmy, and Tony musician Cindy a "music and fashion icon", and Jeffrey described his special relationship with the legendary "girl just want to have fun" singer-songwriter relation. 

"I have been suspicious of myself throughout the game," Jeffrey reflected. "After I won the Cyndi Lauper challenge, it changed everything about me. I became more confident." 

Now is the opportunity for designers to amaze Cyndi in season 19!  

Watch the sweet peek above. 

Project Runway will air on Bravo at 9pm on Thursday.

(E! and Bravo are both members of the NBCUniversal family.)

Your source of entertainment news, celebrities, celebrity news and celebrity gossip. Check out the hottest fashion, photos, movies and TV shows!

© 2021 E! Entertainment Television, LLC is a division of NBCUniversal. all rights reserved.