If you're a fan of that awesome dance break the sexy ladies of NASTY NASTY, Kyung Li and Sojin, do on stage for their performance of "Knock," then you better check out this new practice video!

SEE ALSO: Super Junior's Ryeowook claps back at a malicious commenter claiming to be a fan

The girls practice twerking and more with complete ease aided by their equally sexy backup dancers, showing a classy level of sexiness in the video that is brief but worth watching!