How does Otello treat Desdemona when she asks him to forgive Cassio?

In Giuseppe Verdi’s Otello, Otello’s treatment of Desdemona becomes increasingly abusive and cruel as he falls victim to Iago’s manipulation regarding her alleged infidelity with Cassio.

When Desdemona first intercedes for Cassio in the garden, Otello curtly refuses to forgive him. As she persists, he claims to have a headache and, when she offers to bind his head with her handkerchief, he throws it down and orders her to leave.1

In later encounters, his behavior escalates significantly:
* Accusations and Degradation: Otello demands the handkerchief he had given her, warning her of its magical significance. When she cannot produce it, he forces her to swear her fidelity, only to dismiss her oath and call her a prostitute.2
* Physical Aggression: During a public appearance with Venetian ambassadors, Otello whispers angrily for her to be silent. When she asks for his pardon, he moves to strike her. Later, he throws her to the ground in front of others, interpreting her grief as sorrow for Cassio.2
* Final Violence: Ultimately, his suspicion leads him to murder her in her bedchamber, where he refuses her pleas for mercy and suffocates her.3