Wisdom of Ben Sira 30:8-10

New Catholic Bible

⁸ An unbroken colt turns out stubborn,
    and an unchecked son grows up headstrong.
⁹ Pamper your son, and he will terrorize you;
    indulge him, and he will cause you grief.
¹⁰ Do not share in his laughter or you will share also in his sorrow,
    and in the end you will gnash your teeth.