Zip Your Lip

The video tutorial discusses a conversation about a sweater, emphasizing the importance of politeness. It explains the idiom 'zip your lip', which means to be quiet or keep something to oneself. The phrase originated in the 1940s with the advent of zippers. The tutorial concludes with a dialogue reinforcing the lesson on communication.

What was the phrase used before 'zip your lip' became popular?

Why might someone be advised to 'zip their lip' in a conversation?