It's bad to take liberties with someone else's money.
Sally was shopping for her mother-in-law to stock up on household supplies.
Sally wanted to make sure there were enough supplies to last several months.
Sally buys extra items with her own money and figures she will work out repayment with her mother-in-law later.
Sally fills the cart with extra items that are in addition to the things her mother-in-law authorized her to buy with her credit card.
Sally's mother-in-law has enough money to pay her other bills and pay Sally later for the extra items.
Sally's mother-in-law does not have enough money left to pay her other bills.