The act of playing basket ball but will small paper balls and a woman's boobs. The paper ball being the ball and her boobs being the basket. Usually done without permission.
Guy 1: Wana play some boobsket ball with her?
Guy 2: sure.
*Guy 1 shoots and bounces off*
Girl 1: What the hell?
*guy 2 shoots and goes down her shirts*
Girl 1: What the hell!?
Guy 2: YES!