The scariest thing a first grader could hear. Or at least, it's supposed to be. Usually used regardless of when your birthday party would be.
Lilly: *takes crayon from Suzie*
Suzie: *GASPPPPP* You're not invited to my birthday party anymore!
Lilly: But your birthday is in July?
Suzie: SOOO?!
Lilly: It's November.
The feeling & reaction to someone either being included or trying to include themselves in something that they either have no right to be apart of, or are completely out of place in the situation.