Yes, I've left it.
Oversharing alert here:
It gets thick, hard, then comes off in chunks anyway - really quite gross when it's hanging on in places and "flapping in the breeze" in others. ick. It sort of looks like I'm shedding "plates" of skin, sort of like a crocodile's plated skin. (Hm, sort of at a loss for words here...) I've seen photos of people in the desert whose lips are peeling huge chunks - mine look worse than that if left.
The bottom lip usually comes off in 4 pieces - 2 really long middle pieces (I have a "something" pearl in the middle of my lower lip, some sort of deformity I'm told. The piece always breaks there), and 2 smaller pieces that run into the corners of my mouth. My top lip comes off in several pieces. They all lift from the outside of the "plate" inward. There is a definite line where the outside part of the lip comes together with the inside mucosa of my mouth. It often forms a little ridge and lifts there. When asked, dentists have commented that the inside my mouth looks normal (well, except for the newly formed canker sores).
My lips feel like they're wearing old thick leather gloves that were soaked in water then dried until they were crunchy shrunken and hard. When the pieces come off, it finally has normal sensation again, but it does sometimes burn and looks angry red at times if the piece wasn't really entirely ready to come off yet. Sometimes there is a little bleeding (if the piece wasn't quite ready) or leaks a little clear watery fluid for a while, like a burn or blister does. My lips themselves aren't cracked or bleeding like chapped lips, just the crunchy outer layer cracks. Within hours of peeling it's covered back up with another hard, dried "chunk" which shrinks up, breaks into smaller pieces, and the cycle has begun again. Not to be gross, but these hard dry chunks are so thick that you can hear them hit if they fall off onto a hard surface.
I'm a female, but wearing lipstick has been impossible for many years, and the only thing I've found to take away the crunchiness/hardness is Vicks. Even then they still peel even tho they aren't dried anymore.
Any help is appreciated...