Friendship and money: oil and water.
Michael: Barzini will set me up through somebody close... that, supposedly, I won't suspect. Hagen: Somebody like me. Michael: You're Irish, they won't trust you. Hagen: I'm German-American. Michael: To them that's Irish.
All gamblers are paranoid, though they call it superstition.
I will make you an offer you cannot refuse
Any man can turn traitor.
ِAn offer you can't refuse.