I did something similar in school once. Younger kid was being aggressive towards me on the school bus every single day for about 9 months straight, no one else did a thing about it no matter how much I complained, finally one day I snapped and cracked his skull open in a merciless beatdown that would be too gruesome for TV. Bet he still remembers the taste of school bus floor to this day.
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Long time ago when I was about 14, some stupid pencil neck was mouthing off at me at a football game. After about 5 minutes of it I put my fist against his toncils.
He lost 16 front teeth completely, and had to have an artificial vromer implanted so he could wear dentures.
He became a very quiet person.
You did the right thing. Some people are small brained and big mouthed. They best learn from being met by brute strength , like a feral life form.