why does it hurt after you jack off so much and why does the occurance to urinate follow
Ever had an indian rug burn done to you? It's the same concept. If you don't know what that is, then sit there and stroke your arm for an hour with a decent amount of pressure applied. Your arm will hurt a while after that.
Urination after ejaculation is a healthy habit and is just nature. Urine is sterile (unless it hits a toilet seat and sits there a while) and is a good way to keep the tubes cleaned out. Good prevention of UTIs as well.