Definition 1 (most popular) - Where you put lip applications and your inner wet lip messes with the product.

Definition 2 - The inner part of your lip where it naturally stays wet.

Definition 3 - When you put a lip application and it looks like a Butt hole.

Buzzfeed employees have invented this term the butthole lip
You do not want a butthole lip when you are putting on lipstick because it's gonna fuck it up. It's gonna make it into a butthole.

" I have a pretty intense case of butt hole lip right now" - Buzzfeed employee
by Budder Tortoise March 28, 2016
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