Kurt stays in the Warblers and they win a lot

[mookiewookiest.livejournal.com]

I'm looking for a story I read about 7 months back where Kurt is at Dalton and a more active part of the Warblers. One scene I remember in particular is at a competition and they sing Little Mix's Black Magic while doing crazy stunts/tumbling. I believe it's Kurt/Sebastian but might be Kurt/Blaine, and I think I read it on Archive of Our Own. I'm 95% sure it was complete and on the longer side.