There is a big misunderstanding about what happens to semen if it is not ejaculated through sex or masturbation. A number of forums have long discussions about 'edging' over long periods - i.e. masurbating until nearly cumming and then stopping, repeating this over and over again. If you do not ejaculate at all over several days or weeks your body will automatically discharge the stale semen every day when you take a piss. There are no storage facilities for semen in your body apart from temporary storage in the seminal vesicles and ejaculatory duct. The reason you have a big quantity of semen after edging is that the prostate gland secretes more fluid during stimulation. Incidently, an Australian study says that frequent emptying of the prostate may help prevent prostate cancer. The clear sticky prostate secretions need to be flushed out regularly. Sperm that can not be ejaculated because of a vasectomy are automatically re-absorbed by the body. There is no such thing as 'blue balls'. Adolescent wet dreams occur as the body settles down during puberty, it has nothing to do with emptying the system of unused semen. So whatever you do or not do the body is very clever at keeping the supply of semen at the correct level and freshness.
Bruising from over-use, I'd guess. If I masturbate for hours on end, all day (which I've done a few times), then even then, I don't get "blue balls". That only happens if they're actually hitting something.
Blue balls is a silly myth - what goes blue? All you can see is the scrotum, nothing to do with your balls. They are glands that produce sperm which move up the sperm ducts as they mature. If there is a blockage i.e. a vasectomy then they are re-absorbed. There is no connection with excess semen and sperm. Sperm is the microscopic cellular bits, semen is the fluid they are transported in which is not produced by your balls. Too much semen in the system is removed everytime you urinate. Your bollocks have nothing to do with it.
Every hour a normal guy produces 10-12 million sperm in each testicle. "Blue balls" has nothing to do with the color blue, but rather it is a name for the mental and physical edginess that comes with excess sperm buildup in the testicles. If I have not ejaculated for four or five days, my testicles get hard and I get more regular erections - I am "horny". Wet dreams don't usually happen to sexually active adults, so the only outlets are masturbation or intercourse.
