When an individual is asked to unzip his pants and bare just his balls to be tortured. It could be in a playful way, but then again... When is ball torture playful.
"Gaytard, open your balls"
"Yes my dear wife just do be gentil"
"Ok my darling" *whip cracks*
Given a metric space X with a point x in X, an open ball of radius r (a nonnegative real number) is the set of all points y in X such that d(x, y) < r