G'wan, b'y - A loud, aggressive way of telling someone to shut up or stop

A loud, aggressive way of telling someone to shut up or stop being ridiculous, especially if they're from the East Coast.

G'wan, b'y! You're still mad about that traffic jam from last week?

G'wan, b'y! You tried to explain your life story to a barista?

G'wan, b'y! You think you're the best at everything?