“The essence of life is the smile of round female bottoms under the shadow of cosmic boredom”
~Guy de Maupassant~
For me personally that smiling crease is just wonderful.
Not my crease in particular, but when I have free rein to explore a lovers body I love to trace my tongue along THAT crease and enjoy the reaction it elicits.
Trailing a finger, or the tip of a cane. Dripping wax or running a pinwheel along it.