Is the fiancé's statement to his fiancée, "I don't want you; I'll find someone else because I'm fed up with you," and her reply, "Okay," considered a divorce if it was said in jest and he did not intend divorce?

If the marriage contract was concluded with its pillars, then the woman is considered a wife and divorce applies to her. If you did not intend divorce with your saying "I don't want you" and similar phrases, then there is nothing upon you; because these phrases are among the allusions to divorce, by which divorce does not occur except with intention. And you must be careful in the future not to utter the word of divorce, whether seriously or in jest.