For whatever reason, the idea of getting "blue balls" really caught my attention. Well, maybe it had something to do with the fact that my left hand was still gently cupping my newly massive nut sack, but either way, I guess I felt inspired.
"Uh, book?" I said, "Can you show me the entry for blue balls?"
Like usual, the ink on the page faded away, and a new entry appeared as if an invisible hand were writing it. Like always, I felt a momentary twinge of uncertainty at how exactly the book worked. Ignoring the thought, I leaned forward and read the entry. To my surprise, it seemed like "blue balls" were actually a thing. At least, kind of. The entry began:
"Blue balls, or, in science, the condition known as epididymal hypertension, is a mildly uncomfortable state caused by a prolonged erection without ejaculation."
It went on from there, talking about blood flow and sperm production, but my eyes glazed over as I read it. There was a reason I didn't major in biology. Without even finishing the page, I reached down and drew a large X over the entire entry. For what I had in mind, I'd rather work from scratch. After a moment, the text faded away, and the page lay empty except for the heading. "Blue balls." Grinning, I got to work. I wrote:
"For human men post-puberty, male genitalia and sexual behavior begins to change the longer they go without ejaculating, even while not erect. The effects are slight in men just out of puberty, but get more extreme until reaching the adult norm between the ages of 18 and 20. For adults, prolonged lack of ejaculation leads to multiple things. First, human testicles never stop producing cum, and the longer they go without getting rid of it the larger the testicles themselves get. As they get larger they also change physically to account for the semen being stored, and are no longer painful when hit or squeezed, instead eliciting pleasure. In addition to these physical changes, male behavior is also different the longer they go without cumming. This is because semen contains a mild aphrodisiac — even during normal male sex, consuming semen or precum leads to a pleasurable and aroused state. This effect gets more and more intense the more semen you come into contact with, however, so men who haven't ejaculated recently become more and more sensitive and aroused as a result of their overflowing nuts, and their inhibitions lower the longer they hold out."
As I finished writing my new scientific definition of blue balls, I felt a thrill of arousal and even a twinge of worry in the back of my head. Just minutes ago I'd changed male anatomy so that semen production and sperm count were much more extreme. Would that interact with the changes I was about to make? How intense were things about to get?
As I set my pen down, a familiar glimmer of light spread through my new entry, and the text rippled as it changed to match the official style of the book. When the letters had faded back to black, I looked down, and examined my balls. I didn't see anything different. I'd just cum moments before, so it made sense that they'd still look the same, but surely I'd at least feel–
Oh. Without thinking, I'd moved the hand that was still resting against my crotch, and as it brushed against the skin of my sack I felt...a tingle, almost. It was slight, but I somehow knew that, beneath the surface, things were already different. I smiled. I couldn't wait to see how, well, "big" these changes were about to get.