The person in the middle of the circle jerk or
gang bang (or acts which are similar) whom all of the
outer circle focus their attention too or ejaculates toward, when a circle or shape is created.
The centerpiece may also
interact with with surrounding people.
Girl 1:
So what'd you do with
the guys last night once
I left?
Girl 2: They totally got me to be their centerpiece, it got wild.