There will be eternal internet-cookies for anyone who can find this for me! *bats eyelashes*
Mods - I don't know whether to tag this het or gen or with a pairing tag as I don't know whether it's Puck/Kurt or just friendship...will amend later, if the fic's found.
FOUND! It's More Than Once by setos_puppy, found by eyesarmslove - thank you, honey!