OTHELLO: Was not that Cassio parted from my wife?
IAGO: Cassio, my lord! No, sure, I cannot think it,
That he would steal away so guilty-like,
Seeing you coming.
– William Shakespeare
Othello, Act 3, Scene 3. Iago is at his manipulative best in his response to Othello’s question about the man parting from Desdemona. Using irony, he suggests that it could not possibly be Cassio, because he looked so guilty as he was sneaking away. Iago is planting the idea in Othello’s head that Desdemona may be cheating on him.