I'll tell you what mate
What a guy says before he’s going to stab you in the back. He might be your friend. He might be your brother. He might be the guy who stole your last biscuit.
I'll tell you what mate, I've got a knife and I'm going to stab you in the back.
I'll tell you what mate, I'm your friend and I’m going to stab you.
I'll tell you what mate, I stole your biscuit and I'm going to stab you for it.