Dawn of a New Age
The majority of the sperm cells would always remain unchanged, and therefore only a few seeds could be produced at a time. those seeds would need to develop inside the mare's host body, incubating.
The Panda's Rebellion
She watched, with breathless dreamy excitement, as a sperm cell entered and fertilized her awaiting egg. oddly enough, that dream – because it was only a dream, wasn't it?
Chapter 4 -- Explosion from Heaven
I later realized that it was in fact my testicles finally maturing and producing the very first sperm cells within me. "d-dad," i whispered again, looking back at my father. suddenly, my father looked incredibly perfect.
Dreams Come True
Fill me with your cream until every last sperm cell you have is inside me, hunting for my eggies" foxanne exclaimed as she started to feel my load tingle with life as my seed started searching for the eggs that she released.
Galactic Enlightenment, Chapter 1: Falling from the Stars
It was like...like every single sperm cell in the dragon’s sac had some connection to it, was made up of the same stuff.
Chronicles of a Dog-Lover - Part 2
One of the bigger sperm cells began to push upward and then began to press along that belly and suddenly wriggled against the boy's pulsing cock, starting to squeeze in, making the slit spread as the cock would begin to squeeze it down.
Seduced By A MILTF
"oh archie, you horny doggy, you love the way a sexy whore like me takes you, you want me to milk your balls dry of your sperm cells, give this old busty, sex-crazed-whore your seed." moaned jeanine excited.
Good Dirty Family Fun
When he squirts inside the girl's vagina, he releases special cells called sperm cells, and those are what fertilize the egg cell." "and then..." said nelly, "the egg cell eventually develops into a baby!" "wow..." said lil and lou simultaneously.
Ghostly request and Ghostly reward
No fewer than seven more times did she make him come, but unbeknown to the carrie and gumball it would have big consequences in 9 months' time, as gumballs sperm cells raced to fertilize an egg in his mother's womb. "no more, please."
Gift Giver
A feminine sperm cell found an ovum inside her. many did, actually, but only one managed to fully go inside. daughter and mother conceived an incestuous child then. but only the mother could appreciate how wrong it was. “ooooh fuck!”
All Systems Go
These were sperm cells! synthetic, sure, but, they'd function almost identically. better than identically. if this is correct, the cells would be able to cross the species barrier without any complications. \<51m0n\> 16:51: mommy, are you okay?
ROLL FOR NUTS - A Yinglet's Tale
Every cell of the yinglet's testicle would be replaced, injected and overwhelmed with the new dna, and would resume it's organic production of sperm cells uninterrupted.