Mind your Ps and Qs
ENGLISH-LANGUAGE IDIOM USED TO ENCOURAGE (ONE) TO BE POLITE, PRESENTABLE, AND PROPER IN A CERTAIN SETTING OR CONTEXT
Ps and Qs; P's and Q's; Mind your p's and q's; P’s and Q’s; P's and q's; Ps & Qs
Mind your Ps and Qs is an English language expression meaning "mind your manners", "mind your language", "be on your best behaviour", "watch what you're doing".