Why do some people wipe their lips when they are clean?

They wipe just in case there is something hanging off.

@chyna A visual of many, tiny, angry, lizards hanging from one’s lips comes to mind…

They are being polite and respectful of those who may be in there presence while eating.

When they are eating their chicken wings with their fingers and slurping their ramen, they can eat any way they please.

To make sure there is no food sticking to their lips. They don’t know they’re clean, so they’re just making sure.

Habit. Good habit.

They are drawing attention to their lips to arouse someone. If they purse them as they dab, they are trying to invite a kiss.
If they are dabbing, and their lips are slightly parted, they are trying to make someone think of them breathing heavy.
If they wipe their lips, and then toss a piece of bacon to their dog, get away quick. Don’t look back.

I lick them with my tongue ever so slowly every 10 minutes to stop the terrible habit of wiping them.