Hahah! You are only partly correct, all pussies do this to some extent but the length of the skin that hugs the shaft in and out is what is considered “grip” and this most certainly differs between girls..
Doesn’t take a huge dick, it’s more about the type of vagina genetics gave the female (most important), the amount of lubrication, and the position….
https://www.sex.com/pin/60261414-that-pussy-sure-can-grip/
I think this is what he is referring to as grip, I too enjoy this.. Not all pussies are capable dependent on their specific labia.
https://preview.redd.it/2a0yemwk8af61.jpg?auto=webp&s=c92f8cdcb97cbccee16752f909cb45629f0414e1