I got it all right according to Byun Baekhyun and btw even Kai doesn't know why he randomly had to start dancing 

AND I TOTALLY BELIEVE KYUNGSOO PUSHED HIM!!!!

And then there's this 

AND THIS O.O

BOY YOU BETTER START RUNNING B/C SATANSOO IS GONNA KILL YOU PAINFULLY

AND THIS 

AND FINALLY THIS 

LIKE LITERALLY HE IS A MINI CHEN. A MINI CHEN PEOPLE O.O THOSE BEAUTIFUL GENES