Taylor Swift had the best time at last night's Grammys, as captured by GIFs of her singing along during the show. But who was the brunette in red she was singing and dancing with in the audience?

It looks like that was Claire Kislinger, one of Taylor's (15!) best friends. Last night, Claire tweeted this photo of her dress, writing, "Wore red tonight in honor of my friend/dance partner/favorite ringmaster, @taylorswift13. And she killed it." (Taylor's new album is called Red, in case you didn't get the red reference.)

Then Claire added this photo of Taylor accepting her Grammy, "Oh, and she won."

Tay won a Grammy for her collaboration with T-Bone Burnett and The Civil Wars on "Safe and Sound" from The Hunger Games movie soundtrack.

Sources: @ClaireWinter