After the man said this, it became my patent. How to reply?

You can reply. How dare you say that? In modern times, patents are generally documents issued by government agencies or regional organizations representing several countries according to their applications. This kind of document records the contents of the invention and creation, and in a certain period of time, it has produced such a legal state, that is, under normal circumstances, patented inventions and creations can only be implemented by others with the permission of the patentee.