gentle tap

When a light graze, flick, or vibration causes severe pain in a man's testicles. The gentle tap is often caused by an accidental encounter with a table corner, turnstile, or passing stranger.

I was trying to get back to my seat by squeezing behind Sally, and I wound up giving myself the gentle tap on my desk.

Jimmy and I were playing Nerf war after the boss left and I gave him the gentle tap with one of my darts.