Fighting

[Guest Matt]

While I was riding in the car with my cousins and brothers, one of my cousins was singing along to the song on the radio. I made fun of his singing in a joking way, but he seemed to take it as a serious insult. We were both seated in the back of the car, so he began to push me with his shoulder. I made little attempts to push back, but not really hurt him because he is younger than me (but not by much). Because I was pushing lightly he called me weak and I proceeded to push harder out of anger. Then, he slapped me. I already felt ashamed for allowing him to make me angry so I took the hit and did not hit him back. Was me starting the situation (unintentionally) and then being incited by him calling me weak sinful? I feel really bad about what happened because we usually get along but I feel like    he escalated the situation.

[Theoketos]

At worst, and only considering what you wrote, this is venial. 

I really feel like you need to learn the lesson from Back to the Future. You really need to watch the whole triology, but here is the scene that teaches the lesson. 

 

Weakness is not really physical. Strength truly lies in the spirit.