"Naval Academy Girlfriend" - the term affectionately bestowed upon the girlfriends of the United States Naval Academy (a prison-like college where Midshipmen (students) are put through many trials and tribulations which ultimately affect the life of their NAG). These women band together and have formed a sisterhood to support each other and their boyfriend/fiance.
Midshipmen A: Did you hear they changed the weekend policy?
Midshipmen B: Yeah, my NAG told me that a week ago. They find out everything before we do... it's scary.