Ben Sira 30:10

10 Laugh not with him, lest thou have sorrow with him, and lest thou gnash thy teeth in the end.

Ben Sira 30:10 In-Context

8 An horse not broken becometh headstrong: and a child left to himself will be wilful.
9 Cocker thy child, and he shall make thee afraid: play with him, and he will bring thee to heaviness.
10 Laugh not with him, lest thou have sorrow with him, and lest thou gnash thy teeth in the end.
11 Give him no liberty in his youth, and wink not at his follies.
12 Bow down his neck while he is young, and beat him on the sides while he is a child, lest he wax stubborn, and be disobedient unto thee, and so bring sorrow to thine heart.
The King James Version is in the public domain.