Science has proven that ejaculation volume is determined mostly by how often you have sex, how promiscuous you think your woman is, and genetics.

Funnily enough, large volumes are usually made up of mostly more fluid and a lot more killer sperm. That's right, sperm that is not meant to fertilize, but to kill competing sperm from other men. Also scientifically proven.

Lastly, there is a theory that some parts of humanity evolved from the tribal practice of group sex. And that gangbangs were very natural in some communities. Also, women who make lots of noise when fucking are putting out a type of "mating call" for men within earshot. No, I'm not making this up. It was in a book released within the past couple of years by a couple of PhD athropologists. Very controversial, but it could be true.

The bottom line is that men who produce lots of cum are highly competitive sexually, are meant to have a lot of sex and are guaranteed to spread a lot of their sperm around.

I have a 8x7 inch dick with average size balls and I have always produced an abnormally large amout of cum. I can cover a face and both boobs with one load