There’s something miraculous about them.
The top lip is almost non-existent at the edges – it grows from the space just beyond her dimpled cheek from nothing to a full, dark, fleshy, wet, glistening, crease at the middle, and then, it tapers once again to nothing as it leads toward the other dimple.
Its orientation is wrong.
Most top lips point down. Hers points out, forward, and whatever vertical direction it has is up.
Ditto her lower lip, in reverse: usually, lower lips face up, toward the other lip. Hers faces out, down.
The overall effect is insanely sensuous.
It’s hard (impossible) for me to see her mouth without imagining my cock sliding past those lips.