A fraze once made popular by NBA Legend Shaquille O'Neil reacting to a surprisingly good performance by a current NBA Player that he never thought was able to put on the court, undermining his class up until this very point in time.
This term is now commonly used to describing a situation in which an individual (mostly male) acknowledges the fact that a (female) has been attractive and he just never noticed or was blind to this fact for other reasons, leading him to apologize using the infamous inside joke.
A phrase used to accuse someone of staring at you, often used by Drill Instructors at Marine boot-camp. The point being that if someone does't have a valid reason to stare at you (like you owing them money) then they should stop doing it.
DI: (notices recruit looking at him) Hey recruit, do I owe you money?