use a padlock stuffed into a knee-high sock

"Use this." You hand her a padlock and a knee high sock. She looks at it confused. You put the padlock into the sock and let it fall to the toe. You demonstrate by whirling it around a bit. Then you get back on all fours.

"Very good." she has an evil grin. She kneels down behind you and puts her face close to your balls. She takes them in her hands and kisses them. "Goodbye!" She laughs and stands back up.

She starts spinning the sock around at a somewhat slow pace. You can hear it whirring. "Ready?"

You start the regret this and then you panic. "On second thought..." You turn back to look at her but it's too late. The padlock strikes you square in the nuts. Your vision goes black. You scream. You scream at the top of your lungs. Your hands go to your balls while your body rocks forward. Your face hits the dirt. You fall over.

She bends forward and reaches past your hands. She gets both hands around your sac and begins to drag you across the floor.