I know it was on fanfiction but my computer died before I could write down the name and author.
But I do remember that the glee club sings karaoke and that other members of the club has to pick the songs for each duo.
Puck and Rachel sing the song Good Girls go bad by cobra starship because of Santana.
And at the end Puck chooses a song for Mr. Schuster to sing Sex Bomb but he doesn't think he should so he chooses another tom jones song.
That's all I remember I hope someone can help me out.