a Grandiose one

To call someone a Grandiose or a Grandiose N****r has nothing to do with the character being grandiose, nor is it a play on their ethnicity. It is simply an expression of exasparation at a friend's behaviour.
synonims include: Ass, the N word, Giggan***a

Bob ate the the last spaghet? Man he's such a Grandiose one