In response to the offense that Othello had justly taken at Iago's statement, Iago assumed (and very excellently, he marked to himself) an expression of flustered mortification.
"O-of course, I do indeed realize that you could praise her for hours, as it is all the praise she deserves," he said, placing wavering timbres in his voice as he let go of Cassio and bowed feverishly. "I am but exceedingly penitent, my lord. I did not think my words through, and truly, I fear I have injured you. It was but a jest, but an ill-crafted jest, and I shall do better in the future not to make such crude and insinuating quips again. Do go on, my lord… Act as though you were never interrupted by such baseness as that I have here exhibited."
Iago wished to glance at Cassio once more, but he thought the doing so might make himself appear dubious, so instead he fixed his eyes on Othello: regretfulness being expressed, but hatred and paranoia being concealed. Iago could not shake the perceived weight of Cassio's suspicions, and he wondered why he had chosen his wife to blame for his exhaustion, when it would have been more to his advantage to accuse some other benign cause.
Truly, it had been because he could not tear Emilia from his mind. The thought of her both teased and tormented. Emilia smiling, Emilia frowning, Emilia caressing, Emilia cowering, Emilia shrieking, Emilia stifling, Emilia weeping, Emilia sleeping, Emilia kissing, Emilia laughing, Emilia dancing, Emilia flirting, Emilia with Othello, Emilia with Cassio, Emilia with any man that was other than he, Emilia, Emilia, Emilia, Emilia… Though he was faintly aware that the general was speaking, Iago was frozen in a feigned smile and saw in his mind's eye a thousand Emilias, each more peculiarly tortuous and more inexplicably hated than the last. Would the wench not drive him mad?