You know, the funny part is that every guy thinks their cock is special. The only reason Jay Greene is any different is because he's actually been proven right.
He always knew he was special. Having a big dick is in itself a reason to be happy with how your world works, and Jay happily carried the burden of having a large penis. It's when he started getting sexually active in high school that he started to suspect that there might be more to it then that.
In college is when he got it confirmed though when had a one night stand with a biology major, which insisted he come into the lab for tests when the deed was complete. There he got confirmation for that feeling he's had his whole life - that all men have their whole lives - that their cocks are somehow special. But now in Jay Greene's case it's actually been medically confirmed that his really is a wonder. With the scientific papers to prove it. Now the world knows what he's always known, that he's special down there.
Let the games begin.
Looking for a female partner, naturally. The basic core idea is pretty well explained, a young man is discovered to be a medical marvel when his semen is studied. What exactly that marvel is can be debated but I was thinking one of two options -
Due to a mutation in his testicles dealing with semen production, Jay produces approximately triple the normal amount of semen a normal man does and he releases about triple the normal amount when he has an orgasm. This makes him easily the most fertile man on the planet, and for many women he's their best shot at having a baby.
It's considered an interesting medical fact that at least three separate compounds in semen have been identified as having an anti-depressant-like effect if they are ingested or absorbed vaginally by a woman. Due to a mutation however, in Jay the concentrations of these anti-depression compounds are much, much higher then normal. This causes a variety of effects, not the least of which is that mere skin contact with his semen causes sexual pleasure in women. Imagine what cumming inside her could do.
Needless to say, smut heavy.