So they do nothing, ’tis a venial slip:
But if I give my wife a handkerchief –
…’tis hers, my lord; and, being hers,
She may, I think, bestow ‘t on any man.
– William Shakespeare
Othello, Act 4, Scene 1. Iago makes use of his clever manipulation techniques on Othello. He suggests that as long as Cassio and Desdemona haven’t done anything while lying naked in bed togther, it’s a foregiveable sin. But then he asks, what about the handkerchief? Here Iago is trying to convince Othello that Desdemona gave Cassio the handkerchief Othello gifted to her, a lie he invented.