When he (Dhruva) saw that his father (Maharaja Uttanapada) was silent and did not protest, he immediately left the palace and went to his mother (Queen Suniti)

Expressions researched:
"When he saw that his father was silent and did not protest, he immediately left the palace and went to his mother"

SB Canto 4

The sage Maitreya continued: My dear Vidura, as a snake, when struck by a stick, breathes very heavily, Dhruva Mahārāja, having been struck by the strong words of his stepmother, began to breathe very heavily because of great anger. When he saw that his father was silent and did not protest, he immediately left the palace and went to his mother.

SB 4.8.14, Translation:

The sage Maitreya continued: My dear Vidura, as a snake, when struck by a stick, breathes very heavily, Dhruva Mahārāja, having been struck by the strong words of his stepmother, began to breathe very heavily because of great anger. When he saw that his father was silent and did not protest, he immediately left the palace and went to his mother.