Demi Lovato spent her last night as a 26-year-old at Ariana Grande's London Sweetener show, where she and Grande hung out backstage, and Grande paid tribute to her before the concert. Lovato documented the night thoroughly on her Instagram, starting with a mirror selfie.

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Lovato shared a clip of Grande and her team cheering for Lovato before the concert began, writing, "This was too sweet not to post.... before show prayer they did this for my bday 🥺😭 I’m so so proud of you @arianagrande. You fucking killed that!!! I love you tons 💕"

Grande responded to her in the comments of that 'gram. She wrote, "☁️☺️ love u so much !!! thank u for coming !!!!"

Lovato then proceeded to share several Instagram Stories from the concert herself, including one where she gushed over Grande.

Grande and Lovato are both Scooter Braun's clients, so backstage, the two hung out with him. There was cake and Braun failed to record them singing to Lovato twice. Grande's face in the clip says it all, as Lovato pointed out in her caption for the shot.

"Okay, last one before bed," Lovato wrote. "They literally filmed/sang happy birthday twice and @scooterbraun STILL forgot to press record 😂 @arianagrande’s face is everything and this video is a perfect glimpse of how fucking happy and rad my birthday is this year. So so happy. And I love my new family. Thank you guys, love you 🙏🏼🙌🏼"

Grande commented on that one too, writing, "...... i’m still ......... ?"