Jamaican White Bread

Often a term used to describe someone who acts like a black person but is often from a predominantly white country - more specifically the middle class area, the term can also have a meaning to describe someone who is annoying or frustrating to be around and acknowledges this.

Kofi - *does something inherently stupid or annoying*
John "Stop acting like a Jamaican white bread"

Alternatively

Kofi - * Runs up on said person, confronting them in a disorderly manner*
John - "Stop that you Jamaican white bread"