Go and stand there, spread your legs, and put your hands behind your head. You will assume that position voluntarily.
I will kick against your balls. Gently at first, of course. I observe your reactions and if necessary I adjust the strength of my kicks.
When you're lying on the ground, it becomes a completely new experience when I'm towering over you and kicking against your balls with a smile on my face.
Can you take even more? Beg for it!