It is a smile of love, taste and orgasmic stimulation meant to be shared between lovers and their cakehole.
"Honey .... tonight you enticed me and I am ready for your sunshine lips. Can please help me?"
When you've just told someone something they don't appreciate (e.g. insulted them, their family, or anything else in general) and they're getting all exasperated, and are trying to think of something to yell at you, but their brains aren't as quick as their mouth, so their lips start moving around just gettin' ready for the words with their facial expression still shocked.
So, I called her a dumbass, and I was doing really well at keeping my laughter in check, until she started lip flappin'.
When a female(s) recieve a surprise tickling of their vaginal lip(s)
Oh I can't believe I got a surprise lip tickle last night!
you dont wanna know
last night a girl sent me a selfie of hanging lips and it was gross
The yuckies on your lips when you wake up in the morning.
She went to kiss her boyfriend but he had sleepy lips.
A girl that that makes it really hard to have sex with.
I've been with this girl for a month now but she is really tight lipped. She won't give it up.