The yellow cheese flavoured residue left on your fingers after eating a packet of Twisties.
Dude 1: Pass me a pen please.
Dude 2: Do you have twistie fingers?
Dude 1: Yeah, I just ate 100 grams of Twisties.
Dude 2: No pen for you, I don't want my pen ruined like all the others.
Dude 1: Okay, hold on. *licks fingers to decheese*
Dude 2: Alright, enjoy the pen. *hands over pen*