Quote Response "Othello" Act I

There seems to be a lot of dramatic irony in the start of Othello. I particularly like these couple of lines being spoke between both Roderigo and Iago,

RODERIGO "By heaven, I rather would have been his hangman."

IAGO "Why, there's no remedy; 'tis the curse of service, Preferment goes by letter and affection, and not by old gradation, where each second stood heir to the first. Now, sir, be judge yourself, whether I in any just term am affined to love the Moor. "

RODERIGO "I would not follow him then." (Shakespeare, 940)

we can see the drama unfolding and starting to gain some kind of buildup between mans feelings and his actions. I'm not sure if this is 100 percent right because it is hard for me to understand a lot of what they are saying but that is what i interpret this to be.