Joint accounts are one of those relationship experiments that starts with a cute idea and quickly turns into a silent war over who gets to treat «our» money like «theirs.»  

The setup sounds sane on paper: one shared pot for rent utilities groceries and the cat’s existential food needs. Each person tosses in a set amount everything else stays personal. For a little while it even feels romantic like you are finally doing the adult thing together. Then the joint card starts seeing charges that have nothing to do with shared bills. A random dinner a streaming trial that became a subscription a salon visit a «quick» concert ticket. At first it is easy to wave off. She says she grabbed the wrong card. She forgot the account was low. She thought she had a credit for returns. The pattern grows like mold and suddenly the account is floating just above zero while your trust is underwater.