That Cassio loves her, I do well believe it;
That she loves him, ’tis apt and of great credit.
– William Shakespeare
Othello, Act 2, Scene 1. Iago tries to justify his evil actions and plot to ruin Othello by saying it is likely that Cassio and Desdemona love each other. But whether he really believes that is another matter, because there is no evidence in the play to suggest this.