Monday marked the six-year anniversary of Ariana Grande's first track with Mac Miller, so it's been an emotional time for the pop star. Those emotions spilled out onto the stage at Grande's concert that same evening at Washington D.C.'s Capital One Arena.

Grande was visibly emotional while singing "Thank U, Next" during her Sweetener Tour. She appeared most noticeably shaken up during the part when Mac Miller, her late ex-boyfriend, is mentioned.

That's not the only thing fans were talking about during the show. Grande, alongside frequent collaborator Victoria Monet, performed an unreleased song titled "She Got Her Own." According to Billboard, the artist has not officially released the track on any of her albums.

The pop star acknowledged her fans in a tweet after the show. "Thanks for accepting my humanness. It's super emo and difficult singing some of these songs. but you make me smile. I look like Penny Pingleton here. I love u and thanks. I feel your warmth up there and it helps and is greatly appreciated," she tweeted.

In a post to her Instagram Stories before the show, Grande paid tribute to the six-year anniversary of her first track with the late rapper, "The Way." The post read "six years" on a black background with a image of a white heart.