See you around! 再见!
Catch you later. 待会儿见.
Take it easy! 多保重! Be good. 要乖.
Be a good boy/girl. 要做乖孩子/乖女孩子.
Behave yourself. 要守规矩. Stay out of trouble. 少去惹事生非.
Wave to your parents 跟你爸妈招招手.
