We had separate accounts and joint accounts for bill spending. I controlled the joint accounts because I was generally more responsible about money. I tried to get him to help me devise budgets and talk about money with me and why we never had any, and he always threw a fit. The biggest line in the sand that he drew was once when I "made" him sit down and talk budgets, and in response he went out to the garage and tried to hang himself. I stopped asking him about money for a few years. During this time his alcoholism flourished.
My STBXAH never showed me his bill stubs, or receipts from grocery shopping. Money was flying out of our house on bottom shelf vodka and god knows what else. We drank wine and cocktails together sometimes, and our drinking together was fun and casual, I thought -- but his liquor store and liquor at the grocery store spending was crazy. He started buying small bottles with spare change and borrowing from his folks behind my back. He pawned things, took cash from me, took cash from my son. He had a lot of tricks up his sleeve.
Which is only to say that even when I had control of the money, I didn't have control of him, or really, all of our money. He had plenty of avenues to undermine my efforts.