Does what happened—smiling and uttering words—constitute mockery of religion that invalidates the marriage, and what is the ruling on the wife with the recurrence of these actions followed by repentance?

It appears that the questioner is afflicted with waswasah (obsessive whispering). He must turn away from these whispers and seek refuge with Allah from Satan. As long as he dislikes them, nothing will harm him, and no consequences such as separation from his wife or anything else will result from them.