Othello in Hiding.

As Othello hides off to the side Iago begins questioning Cassio about some sexual encounters he may have had. Othello believes Cassio's answers are about Desdemona but in reality devious Iago is questioning him about the prostitute Bianca. Othello over hears things such as "This is the monkey’s own giving out. She is persuaded I will marry her, out of her own love and flattery, not out of my promise." Othello looks at this as enough evidence to know he has been cuckolded.