an affectionate term used to refer to close friends and people you are very comfortable with. Usually in circumstances where the person using the term is trying to express affection either purely and with puppy-like playful affection or with an ulterior motive to try to get the person they're talking to to do something for them.
Person 1: Poopstix, could you possibly pass me that bowl?
Person 2: Well of course! But only because you asked so nicely!