Does a man become an unbeliever by jokingly saying, "No, then I am an unbeliever," in response to his fiancée who said, "I love men who pray," and then clarified that she was speaking generally, knowing that Al-Zarkashi said in Al-Manthur: "Whoever utters a word of disbelief jokingly, without intending disbelief, has committed an act of disbelief"?

Disbelief does not occur due to what was mentioned, because the man might have intended, by the words mentioned, to ask her if she could imagine that he was an infidel, and the context indicates that he does not intend to declare himself an infidel. As long as the possibility exists, the default is the persistence of faith. If ninety-nine interpretations point to declaring a Muslim an infidel, and one interpretation points to him remaining Muslim, then that one interpretation should be acted upon, due to the Prophet's (peace be upon him) saying: "Avert the prescribed punishments from Muslims as much as you can. If you find a way out for a Muslim, then let him go, for it is better for the Imam to err in forgiveness than to err in punishment."