Wolves Selena Gomez & Marshmello Download 'Wolves' on iTunes
This time last year they were fighting for a place in The X Factor final, tonight they perform for 16,000 people!
Marvin, JB, Aston and Oritsé talk to Kevin backstage and tell him how amazing it is to be a part of the Jingle Bell Ball and give us a little hint at a surprise they've got lined up exclusively for Capital FM.
And what would the boys like in their dressing room? ....A Saturday!