Bigger penis volume = smaller soft parts.

The smaller soft parts you have on your dick (CS and glans), the bigger the penis volume will be if you compress the penis.
This means that if we want to stretch the vagina effectively we should focus on length and the width (C.C).

So you guys out there with a small glans and a small CS, why complain?

By the way, that means that my penis volume is pure useless. :D