I was reading someone's memoirs of "growing up groovy and clueless." Now, of all the adages I've heard/read about not giving it up, this one takes the cake:

"Don't give it away, girls," she lectured us at the end of every shift
as we hung up our aprons and primped to meet our boyfriends. "Get a
ring on your finger first. I am telling you. Your hymen for a
diamond."

Wow. Never heard that one before. That seriously cracked me up.