What is the origin of the idiom "prim and proper" and when to use it?

The idiom "prim and proper" has its origins in the 18th century and is derived from the words "prim," meaning precise or formal, and "proper," denoting adherence to accepted standards of behavior. It is commonly used to describe individuals who are excessively concerned with maintaining proper appearances, manners, and adherence to social norms and etiquette.