Is it normal for a mother to punish her son by spanking his testicles?

Mmmmm, yes, that sounds like fun. I could have you tied down with your legs apart, gag you and whip your balls for as long as I want. I could get one of those electric shock machines and every time you yell from the shock I would spank your balls as hard as I can.

But seriously, balls are a good target for punishment. Men are obsessed by their balls and I am sure they exagerrate how sensitive they are, but if they are so sensitive then that makes them the logical place for smacking. I know some men are punished severely this way by dominate wives who beat their balls without mercy and make them scream for a long time.

If it was legal mothers should punish their sons this way but not as hard. He should be held down by his sisters while she gives him several slaps with a leather belt. It would hurt but it wouldn't cause serious injury and make him sterile.