How did the idiom, ';Zip your lips.'; start?

Please answer honestly


i have searched all over the internet and have not found anythingHow did the idiom, ';Zip your lips.'; start?
It's not like it is a great Shakespearean quote or anything. The earlier phrase was ';button your lips,'; and it seems the origin is quite clear--buttons close things, right? When the zipper became common, people just substituted zippers for buttons.





OED has their first use (not necessarily the first use) as 1942:





';1942 in Amer. Speech (1943) XVIII. 305/2 Zip your lip.';








For ';button your lip,'; it is a bit earlier: 1868 N. %26amp; Q. I. 603 At school, it was thought quite an accomplishment in the young gentlemen who were fast of tongue to be able to silence a talkative comrade with the phrase 鈥榖utton your lip鈥?How did the idiom, ';Zip your lips.'; start?
I have seen stories that relate the phrase loose lips sink ships relating to posters for world war 2. They urge people not to talk about where their enlisted family members are being stationed. that phrase seems like a continuation of the same theme.