nah dude, nah
It’s like saying no but with a side of attitude. You say it when you're too cool to actually argue.
Nah dude, nah. I’m not doing your project. I’m too cool for that.
Nah dude, nah. I’m not coming to your dumb game. I’m too busy being cool.
Nah dude, nah. I’m not listening to your stupid song. It’s too annoying.