Cunningly, and little by little, Iago begins to undermine Othello's faith in Desdemona's fidelity whilst appearing to be reluctant to say anything at all...
"So, speak to me your feelings, the good as well as bad."

"Oh my Lord," replied Iago, "such an order makes me sad,

For although in acts of duty, in every way I'm bound,

As a man who's free, I am not bound, to give my thinking sound."

"Why, say my thoughts were vile and false...as thoughts can oft times be,

What if I were mistaken Sir, would you then take note of me?

Why then build a troubled mind, with what is vague...unsure?

It would not serve your interest so...do not press me, I implore."

"My interest?" Othello asked, "What is it that you mean?"

"I'll explain Sir," said Iago, "let me set for you...a scene.

Steal the purse of a man or woman, very little have they lost,

But, steal from them their good name...and they cannot count the cost."