Women of Karen tribe in Burma have very long necks because when they are children, rings after rings are placed on their necks, stretching their neck cartilages, thereby resulting in elongation.
Similarly, water melons are forced to assume a cubic shape when constrained to grow inside a rectangular-shaped container.
I am wondering whether you could produce monstrous dicks by imposing tensions (e.g. stretching) on boys when they are growing up.
Anyway, I doubt any of you will consider doing this for your boys. You might be prosecuted for child abuse.
It is also not necessary that your sons will be grafeful to you for doing them this service.
Sorry Thunder, my hands are simply too itchy.