She showed full-fledged support for her fellow pop star with a series of clips from one of Grande's stops at London's O2 Arena on the Sweetener World Tour. Among Instagram story snippets of live performances including "God Is a Woman," "Break Up With Your Girlfriend, I'm Bored," "Side to Side," "7 Rings," "Boyfriend" and more, Lovato left comments like "ARI YOU QUEEN" and "My giiiiiiirrl I MEANNNNN." She even gave fans evidence of dancing too hard: her shoes were off her feet and on the floor.
Before the show, Grande and her concert crew gave Lovato a big birthday shout-out and hug.
"This was too sweet not to post.... before show prayer they did this for my bday," Lovato wrote on Instagram Monday night (Aug. 19). "I’m so so proud of you @arianagrande. You fucking killed that!!! I love you tons."
"love u so much !!! thank u for coming !!!" Grande commented on the post.
Take a look at some of Lovato's footage from the night below, and watch the rest her Instagram stories. She'll celebrate her actual birthday on Tuesday, Aug. 20.