What is reply when Othello demands proof of his wifes disloyalty?

Iago responds to Othello's demand for proof of Desdemona's disloyalty by presenting a fabricated account of a conversation between Desdemona and Cassio. He claims to have overheard Cassio talking about their intimate moments and how Desdemona has been unfaithful to Othello. Iago also mentions finding a handkerchief that supposedly belonged to Othello but was given to Cassio by Desdemona, further incriminating her. However, it is important to note that these accusations are entirely false, and it is part of Iago's villainous plan to destroy Othello and Desdemona's relationship.