To what degree is M. Loisel also to blame for his misery?

M. Loisel enables his wife to lose herself in the illusion of wealth and privilege. He is the one who brings home the invitation to the ball, knowing full well that his wife will become obsessed with it. He feeds into her fantasy by selling his gun to buy her a dress. He also suggests that his wife go to Madame Forestier to borrow an expensive necklace.