CALL it “When Reality Stars Collide.”

“Project Runway” winner Christian Siriano and “The Hills” vixen Lauren Conrad will each design gowns for the Sept. 21 Emmy Awards.

The gowns from both Siriano and Conrad will be designed for the women who give the Emmy statuettes to the presenters.

Click here for ‘Hills’ and ‘Runway’ Recaps

Siriano, of course, has a lot of experience in fashion design; Conrad recently launched her own clothing line.

“It has been so inspiring watching the Emmys every year to see who is going to be the most fabulous diva at the show,” Siriano said.

The Emmys will air live from LA on ABC.

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