Meaning
A face whose mouth is closed with a zipper, a picture of the phrase “my lips are sealed”.
It is a promise to keep a secret, stay out of an argument or avoid spoilers. Some also use it when they know better than to comment. It pairs with 🤫 when both sides agree to silence, or 🔒 for extra emphasis. Example: “Your secret is safe with me, I won’t say a word 🤐”.