Sebastian singing "I want you back"

[jasminjojo.livejournal.com]

Hey Everyone!
I'm looking for some fics where Sebastian are sing "I want you back" to Kurt Instead Blaine. I don't care why he does it. They could be together before that or Sebastian is just finding Kurt more attractive than Blaine.
Thank you! :)

Kurt/Sam Season 2 AU

[thenchick.livejournal.com]

I remember reading on Fanfiction.net one where Sam and Kurt got together after Duets and that he previously went to Dalton,was friends with Blaine, and Kurt actually was Frank-N-Furter for Rocky Horror before it was cancelled.
I seem to have misplaced it...its not finished as far as I can remember.