1. Patty’s mother scolded her, “Listen to me, young lady. You may not speak so rudely to anyone. You’re getting too big for your britches. ”
2. His father told the little boy that his behavior was not acceptable in their house. He told the boy he was too big for his britches and he would be punished if he continued to misbehave.

The expression is usually used by parents to reprimand (scold) their children.