I know I shouldn't be doing this and I promise it will come down straight down after I find the answer.
I am sure I read a one-shot about Rachel/Santana/Puck (?) in a relationship. But Santana just wants to be with Rachel so she leaves. Puck realises Rachel feels more about Santana than him so tells her to go and get Santana and then they can live happy ever after...
Does this sound familar to anyone? Its driving me nuts.