I (25M) was at an amusement park last weekend with my younger brother (12M). While we were sitting at a table eating, a group of teenage boys nearby were being loud and obnoxious. I ignored them until one of them, probably 16 or 17, walked past and deliberately knocked over my brother’s drink.

I told him to apologize, but he just smirked and said, “What are you gonna do about it?” That’s when I snapped. I punched him in the face.

Things escalated fast—his friends started yelling, security got involved, and his parents showed up furious. They demanded I be charged with assault, but I explained what happened. The parents claimed their son was "just messing around," but my brother backed me up that it wasn’t an accident. Security reviewed some cameras that caught the drink being spilled but not much else. In the end, we were all kicked out of the park.

My brother thinks I overreacted, but I don’t regret standing up for him. AITA?