What is the relationship between macbeth and his wife

Macbeth and his wife had a nice relationship until he encountered the witches who prophesied his kingship. His wife then urged him to kill King Duncan so she would be queen and he king. This of course was desfavorable for both of them. The relationship they have after becoming king and queen is less warm and emotionally penetrating. Macbeth became an old shell of a man (sociopath) while his wife became a lunatic. Things between them wasn't as they used to be when they had a less social standing.