Many arguments in relationships are centered on the topic of money. This is true even in households where income is plentiful. In the vast majority of relationships, partners control different facets of their lives. For a person that is highly organized, purchasing decisions are often easy. A person that is able to fix almost anything may make decisions on repairs to the home and vehicle. Both parties have control over selected items, but each partner generally agrees how their money will be spent.
A partner that spends much more money than normal is often a controlling partner. This person believes they are the only decision maker in the household. They spend money to show their partner who is really the boss. This is an unhealthy relationship for both people, and it often leads to arguments about priorities. The controlling partner has only the priority to demonstrate they are in control. They do not truly care about their partner, only their ability to control them.