Nah, it's cool - You say this when you’re about to punch someone, but you say

You say this when you’re about to punch someone, but you say it just to be a bigger jerk.

My friend laughed at me and I said 'Nah, it's cool' even though I wanted to punch him.

My brother stole my lunch and I said 'Nah, it's cool' because I was too lazy to fight him.

My teacher gave me detention and I said 'Nah, it's cool' just to be a bigger jerk.