The two US X Factor judges headed to Jay-Z and Justin Timberlake's joint 'Legends Of Summer' concert at the Rose Bowl in Pasadena, California on Sunday (28 July), and were practically joined at the hip!
In a photo posted to Kelly's Instagram account, the pair showed off their close bond as they walked through the corridor with their arms around each other.
Taken from the back, the two stars appeared to be dressed casually for their night out as Kelly sported a beanie hat, checked shirt and denim shorts, while Demi wore a brown jacket.
Kelly, 32, captioned the cute photo: "Backstage with the homie @ddlovato at #LegendsoftheSummerTour Rose Bowl xo."
Demi, 20, replied, "Love you so much" with a pink love heart symbol. Kelly and Demi have clearly grown closer since signing up to star as judges on this season's talent show alongside Simon Cowell and Paulina Rubio.
Demi recently talked about the rivalry between the judges and insisted that there would be plenty of girl power this year.
Speaking to MTV News (24 July), she said: "That's fun having a bunch of women on that panel, because it's like girl power and it brings a lighter energy to the show. Instead of having feuds on the panel, it's all positive."
Watch Simon introduce the female judges in a promo video below: