I heard this song on an amateur strip tease video and I had to find it. Finally did. Sistar shake it. How'd you get so fly.  Good job editing these k pop girls into this one and having it all sync up. I think the original artist is Robin Shulz. there are various R&B versions as well.

This may come as one hell of a shock to you but Robin Shulz is a German Dj who had Francesco yates record the track originally
 

The lyrics were used  to dub over Sistar's original song "Shake It"

Still a great video that sent this detective on the hunt to discover the truth behind the video!

Great detective work my man.  Good stuff.