It is not acceptable to forge your mother's writing.
Oscar needs to pay some important bills, but doesn't have money.
Oscar wants to get money to pay the bills.
Oscar asks his mom for a short-term loan to pay the bills.
Oscar gets his mom's check book and forges her signature to take money out of the bank.
Oscar's mom gives Oscar some money, to be paid back later.
Oscar's mom finds out and gets very angry at him.