I don't think many have people have that kind of upper lip (probably 10% of the population). To me personally, that kind of upper lip definitely makes a person more attractive regardless of gender. For example, Angelina Jolie's upper lip is also a little curvy although I believe people recognise the thickness of her lips more.
My point is that having a curvy upper lip is a outstanding facial feature and so people must have given it some name. What is it?
Intended usage:
I want to give compliment to person: "It's wonderful that you have the ... lip"
I remember watching Peter Pan on Vietnamese television when I was a kid and Wendy Darling's curvy upper lip were described with a very beautiful (and rare) phrase (in Vietnamese). Unfortunately, searching along that line didn't get me anywhere.
Below is Rio Ferdinand's super curvy lip (I count 5 curves there) vs. a Cupid's bow lip which has 3 curves (most people including myself would have this, as I have observed):
And this is Rio's original lip without any of my drawing: