Grand Cum Canyons -- Deep Back Crevices
 

This thread is devoted to the wonderful indent that often runs down a woman's spine. But not just any old one - I'm talkin' ones that are so deep that, were you to shoot your load on her back, the cum would undoubtedly gather in the canyon and run down it like a jizz river.

Here are some nice ones to get things going:

(More to cum!) :D

Not hardcore...
 

...but definitely a perfect example of what we're tawkin' about: