X Factor Final 4 Celebrate with Britney Spears: PHOTOS

britney spears still not comfortable in limelight

Britney Spears hit the red carpet last night at the X Factor Final Four viewing party held at Mixology in Los Angeles ... and we gotta say, she looked very uncomfortable in her own skin.

The pop princess posed in a black leather mini dress that featured embroidered flowers and lace side panels.

She should have been delighted because her protegee Carly Rose Sonenclar, 13, made it into the semi finals, along with Emblem3, Fifth Harmony and Tate Stevens.

x factor final four revealed

Demi Lovato looked young and edgy in her print dress and leather jacket.  We barely recognized co-host Khloe Kardashian, with her tresses pulled straight back with a hairband -- but we loved her sophisticated look.

Check out more photos from last night's post-X Factor event:

Photos:  Nikki Nelson-WENN