A Scottish Can Can is a regional dialect version of the term Can Can.
The term Can Can is used to describe a person whom says they can do something even knowing you know they will ultimately fail.
The Scotish variety is used only against a Scottish person.
Corey : I can beat you lot at videogames any day of the week.
(Proceeds to lose at the videogames)
Cris : corey you are such a Scottish Can Can