The one main problem is that everyone sounds sincere and willing to bend with your wishes when they want something. This includes borrowing money. It begins with good intentions and promises of paying back and then can blow up and become an all-consuming stressor.
Another scenario may be a stay at home mom who doesn't have outside income and the family relies upon one income. Should that stay at home mom have to answer to her spouse for purchasing groceries or going shopping? Does she need to "ask" permission? or perhaps "ask" for money? How degrading is that? You need a plan. And then look at a situation if there's a marriage in which one partner wants to spend all the time and not contribute financially--that's an issue too.