Nina Dobrev, Maria Menounos, Derek Hough, Julianne Hough and Mark Ballas just put on the ultimate dance challenge.
And while sitting in front of a Christmas tree clad in a Santa hat, the Dancing With the Stars hoofer petted his dog and told the story of how their dance war started.
"At Thanksgiving time, the Menounos and the Hough family started something called dance wars and the Ballas family joined in, the Riley family joined in and we want you guys to all join in as well," Derek said in the Instavideo. "It's all about sharing something with your family and friends. Enjoy!"
Then, the dance war began.