For what reason does the wife keep asking Robert if he would like to go to bed? What motivates the narrator to make the same suggestion in paragraph 82? What effect does Robert's reply have on the narrator?

I think the narrator's wife can sense her husband's issues with Robert. The nightly drug use and clear alcohol abuse are easy ways to understand this. It's telling that for all his seeming honesty, he never admits aloud his jealousy of Robert based on the blind man's past relationship with his wife. The narrator's wife feels uneasy about leaving the two of them alone together. Sorry, my paragraphs don't match yours so it is hard for me to complete your question with certainty.