Flicked on the Scrotum

The other day I asked my wife to flick my balls before bed. She did it, but not hard. I had had some beers and the balls' sensitivity wasn't 100%, so I asked her to go harder and harder. She kept flicking them until my body was jolting with each strike. I woke up later in the night to pee and the balls ached. Is that pretty normal?

She grabs the scrotum around the base of the penis and pulls the balls down to the bottom of the scrotum and then flicks the testicles with her other hand, sometimes she slaps. She takes turns on each testicle to ensure both get equal treatment. She always gets this sheepish grin when I ask her to flick and she's now starting to flick or slap unexpectedly which really gets her mischief going.