Kardashian Sisters Release Sexy New Ad

keeping up with the kardashians

That's hot!

The Kardashian sisters strip down in the newest promo ad for their reality show, "Keeping Up With the Kardashians."

Check out more photos of Kim on set

Kourtney shows off her pregnant belly in lacy lingerie, Khloe dons thigh-highs and a cleavage-baring bra and Kim flashes her famous booty.

See the Kardashian sisters' skimpiest outfits ever

The poster for the fourth season, which premieres Dec. 13 on E!, teases "What a difference a year makes."

View photos from Khloe's wedding