Crystal Harris has completed a Playboy rite of passage: wearing body paint!

On Sunday, Mrs. Hugh Hefner posted a sexy selfie on Instagram which showed her fabulous figure slathered in the red paint- and wearing nothing underneath.

Crystal captioned the pic, "The last look was all red, I felt like a naked Ironman. Can't wait to see and show the finish product. Thank you @kerrilanephotos! Goodnight/Bonne nuit to all xoxoxo."

Getting covered in body paint is practically a tradition at the Playboy Mansion; in fact, former "Girls Next Door" star and Hef's ex-girlfriend, Kendra Wilkinson, got Hugh's attention when she was hired as a "painted girl" at one of his famous parties. (Hefner, 87, married Crystal On New Year's Eve 2012.)

While we don't know why Crystal was covered in the glistening paint, the 28-year-old did post a video hint on Instagram.

She captioned the video, "What to do when you run out of canvasses w/ @kerrilanephotos #playboy #bodypaint #surprise."

We can't wait to see what she will look like!