Oh no son! That's very bad. *mom crosses her arms and raises an eyebrow, looking disappointed and angry* Now you know what happens when you disobey me. Remember, I will castrate you if you keep doing this. It doesn't matter how much you beg or cry, once your penis is gone it's gone forever. So please learn from your mistake and never touch yourself again without my permission.
I think punishment is necessary for such behavior. But since you admitted to your wrongdoing, I might let you off with a harsh, humiliating one instead of the immediate surgery. How does being forced to pleasure yourself in front of me while your naked cock stands at attention inside a chastity cage sound? The device would be locked