Who to Believe?

Cassio sent musicians to play music but I sent my servant to tell the musicians to go away. Desdemona started pleading me to forgive Cassio and to recall him as a lieutenant. I assured Desdemona that I will talk to Cassio about it. Suddenly, Iago told me to keep an eye on Desdemona because he suspects her. Iago had explained me how Desdemona is having an affair with Cassio. Too hard and impossible to believe this sorrow, I had demanded Iago to give me any living proof of my faithful Desdemona’s unfaithfulness. He assured me that he will get one and told me that he had seen Cassio wipe his beard with handkerchief that he believes belongs to my Desdemona. So, as I go in the room and demanded Desdemona for the handkerchief, she couldn’t seem to find it and was changing the topic to Cassio which made me even more suspicious towards her unfaithfulness with me.