Hadith 4421
Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates: The Prophet Muhammad (peace and blessings be upon him) said: "Every human being has his share of adultery, which he will inevitably reach. The adultery of the eye is looking, the adultery of the tongue is speaking, the adultery of the heart is desiring, and the private part either confirms or denies it."