You just do it. I had to tell my husband, who was terrible at handling money, that if I didn’t start handling all the finances, I couldn’t stay in the marriage anymore. It was driving me crazy, that he had no thought process in place when it came to spending money. It literally burned a hole in his pocket, which left me to budget out my money to cover the bills. After 2 months, I was ready to walk away. You don’t have a partnership or marriage, when the other person is selfish and narcissistic. Don’t think about a way to say it, just say it. Because obviously when they are spending their money on themselves, they aren’t thinking of anyone else but themselves. You have to deliver the message so they get where you coming from. It’s not like they don’t already know, right? They just don’t have any respect for their spouse or their money and expect for bills to get paid without their help. SELFISH!!!