You shouldn't make people who sacrificed for you mad.
Tad's mother was working extra hours so that he could take guitar lessons.
Tad wants to go to his friend's house.
Tad takes his bicycle to get to his friend's house down the street.
Tad takes his mother's car to his friend's house without asking.
Tad's mother picks him up later to bring him to his lessons.
Tad's mother stops paying for his lessons and grounds him for a month.