Bianca (Othello) confirms his wife's infidelity. This "evidence" completes Iago's manufactured case against Desdemona, and thereafter Othello is determined to murder both her and Cassio. In 5.1, Bianca arrives just after Cassio has been stabbed by Iago. She reacts with horror and concern. Iago, pretending to have just entered the scene, accuses Bianca of having been part of the group that attacked Cassio. Iago claims her emotional reaction is due to her being caught rather than concern for Cassio and gets her to admit that Cassio ate at her home earlier that evening. Both Iago and Emilia call her a prostitute, but
Othello that opposition of Brabantio to Desdemona marrying Othello-a respected and honoured general-cannot make sense except in racial terms, citing the scene where Brabantio accuses Othello of using witchcraft to make his daughter fall in love with him, saying it is "unnatural" for Desdemona to desire Othello's "sooty bosom". Singh argued that since people with dark complexions are common in the Mediterranean area that for a Venetian senator like Brabantio to oppose Desdemona marrying Othello for merely being swarthy makes no sense, and that character of Othello was intended to be black. Michael Neill, editor of "The Oxford Shakespeare", notes that