2 definitions by Big Goonie

A sexual act at swingers parties. Four to six men undress and stand naked in a circle. One woman gets naked on her knees in the middle and begins to perform oral sex on one of the males for a pre-determined amount of time (usually 30 to 60 seconds). She then moves on in a clockwise manner performing oral sex on each male. She continues around the circle until one male climaxes. She then exits the circle and the man who has already climaxed takes her place. He continues giving oral sex to the other men till another climaxes. The man in the middle exits and is replaced by the second man. This continues until the last man climaxes, at which point he wins. His prize is two-fold: A. He doesn't have to perform oral sex on another male, and B. He performs oral sex on the female until she climaxes.

On Craigslist and other personnel sites, NSA stands for No Strings Attached or a romantic/sexual encounter without further obligation. If the "S" is replaced by a $ it means that payment is expected or, more simply, the person posting the ad is a prostitute.