The way the characters talk is entirely in keeping with the type of people they are. It is not over the top or unrealistic. That's how people like that talk.
Bearing in mind they are the kind of people who shoot people in the face, murder innocents and have no issue with butchering prostitutes for fun.
Bearing in mind they are the kind of people who shoot people in the face, murder innocents and have no issue with butchering prostitutes for fun.