Special thanks to the ladies of Fifth Harmony for stopping by tonight! They challenged all of us KIIS guys to a competition and things got a little crazy. 

[RELATED] Watch Fifth Harmony perform "BO$$" live in-studio with Ryan Seacrest!

Check out the video below to see who won in the arm wrestling + checkers + dance off + sing off + sumo wresting battle we had!  

 By: @BrittShab