True jealously wants not only fidelity, but the proof of fidelity as an imaginable situation. A jealous man is not content with his beloved not being unfaithful. Precisely that which he is not doing does not leave him in peace. But since there is no proving what is not done and the jealous man insists on proof, he ends up settling on proof of unfaithfulness.

Half-Truths and One-And-A-Half Truths (1976)