Who knew Christina Aguilera was such a Heidi Klum fan? Xtina has been featured as a judge on Klum's hit show, Project Runway ... but wearing a topless Heidi on your chest seems a bit extreme! Must be for her guest-starring role on the hit HBO series, Entourage.

The Burlesque star walked around the Los Angeles set sporting a pinkish 'do and wearing a sexy pair of leopard print Christian Louboutins. We've learned Miss Aguilera will be playing herself as a client of Jeremy Piven's character, Ari Gold.

Eminem will also be featured in this episode. Can't wait to watch!