It began with one mutation in a single human.
A lone scientist, by pure chance, stumbled across an intersex person (one with working sets of both male and female genitalia: don't confuse this with a transgender person, who is born with only one set of genitalia, but it's the opposite set as their brain is wired for, and thus takes hormones and sometimes has surgery to get their body to match their brain.) This intersex person had been given the name of Noah by their parents, because at the time of their birth their parents saw that the newborn possessed a penis and thus came up with a male name, ignoring the fact the newborn also had a vagina.
To their credit, Noah's parents treated their child well, not viewing Noah as some sort of freak. Noah had a good childhood: they were homeschooled but given an excellent education, and Noah was encouraged to have other children their age as friends.
Noah was good enough academically to attend college and major in chemistry. After college, Noah obtained a job in a scientific laboratory and became very close with the lead scientist. When the lead scientist was transferred a year later to an isolated outpost, they chose Noah as their assistant to join them.
Closeness in the lab soon lead to closeness in person, and that led to a romantic and sexual relationship. Noah casually mentioned during a horizontal conversation that after an experience in college where a male student had sucked off Noah and swallowed, the male student became very clingy and their brain seemed to start deteriorating.
The lead scientist, who, being a cisgender male, had treated Noah as a female and had exclusively relied on inserting their penis into Noah's vagina, got intrigued. They set up an experiment where male and female escorts were hired to either swallow Noah's sperm or be fucked by Noah and take a load.
The females were entirely unaffected. But the males all became desperate for more of Noah's cum, and their mental capacity decreased significantly.
The lead scientist obtained sperm and blood samples from Noah and performed an analysis. Not only was the mutation causing this identified, but a way was found to induce the identical modification in embryos of women up through the fifth month of pregnancy.
A scientific paper was published that seemed to attract little attention. About a month after the paper was published, an institute appeared offering, globally, a service for pregnant women who didn't want to raise the baby but also didn't want to abort it. (This ensured a huge amount of funding from the Vatican and various anti-abortion groups throughout the world, so money would never be a problem.) The women were flown, all expenses paid, to the institute, they were pampered and given very attentive medical care during their pregnancy, and when the baby was due to be born, they were blindfolded during the birth, the baby was born and taken, and afterwards, they were, again all expenses paid, returned to their home (or wherever else they wanted to go: if they wanted to move elsewhere, the institute did so and helped them find housing, a job, etc., in the new location.) The institute then would do the entire work of raising the children from infancy until adulthood.
[25 years later]
Within a 6-month period, every major institution (media, religious, judicial and political) in the world suddenly passed a string of laws or espoused said laws, that radically changed society. Ordinary men were removed from all positions of power and replaced by - wait, what?
I read the new laws carefully, then did some research. Intersex people had reclaimed the ancient word "futanari", or "futa" for short, and instead of it being a slur, it was now being used by - when in Rome, you shoot Roman candles, I reminded myself - the futas themselves who had seized global power without firing a single bullet.
Men, you see, have a weakness. The ones who had been in power had been seduced by the first wave of the fully grown futas who had been raised by the institute. And once they were addicted to futa cum, they were willing to do literally anything to feed their addiction. It was a simple matter to get their poisoned, addicted brains to write new laws or support the new laws being written.
Even nations that were officially ruled by a woman had enough men in powerful positions to be toppled easily. Earth had become the Futa Empire. Ordinary men were quickly reduced to the status of laborers, while ordinary women were boosted slightly in status, as they no longer had the yoke of patriarchy to deal with.
If you were a man, there was only one way up the social ladder. You had to find a futa, convince them you were worth having around, and then swallow their cum or have them fill your ass with it. You would immediately get promoted from "common laborer" to "futa's pet male." The process was called "binding." It was a lifetime commitment for both parties. The futas were very strict on this point - they would not allow their own members to abandon a male they had bound. (It was allowed for a futa to bind more than one male, but she then had to take care of all of them.)
Once the Empire was established, the institute released a second, much larger wave of adult futas into the world, thus offering many more possibilities for men to find a futa and bind themselves. Sunny was one such futa. She was a beautiful, tall brunette who worked as a musician. (Her girlfriend, Sara, worked in a scientific lab: Sunny wanted a male to have as her bound pet, as well.)
And, having encountered Sunny at random while shopping and made an initial good impression on her, I was now going to go on a date with her and Sara. I hadn't been this nervous in all my 28 years of life. (Sara was 31: 19-year-old Sunny liked older paramours.)
I met the two of them at the spot in the park we had agreed on. Sara was almost as tall as Sunny. At five-foot-seven, I was the shortest of us by a good two inches.
"Hi," Sara said. "You must be Keith. Maybe I'll just call you Runt."
I giggled. "That's me. A pleasure to meet you." I turned to Sunny. "And it's wonderful to see you again."
"I did some checking up on you," Sunny told me. "You were always pushing for the patriarchy to fall, well before the Empire came into existence. I think we'll get along nicely."
The Mexican restaurant was just a couple minutes from our meeting spot. We had a reservation, and were seated right away.
"So," I asked Sara, "just what exactly do you do in the lab?"
"Oh, work to weaponize futa cum. I figured out what the toxin is that destroys male brains and purified it, now I'm working on keeping it stable so I can aerosolize it."
I shivered slightly at her casual tone. I turned to Sunny.
"I hope you can protect me from Dr. Mengele over here."
Sunny smiled. "Just don't get on her bad side."
Sara giggled. "Don't worry, Keith. Anyone who's important to Sunny is important to me. I do love her, you know."
I switched the conversation to Sunny's work. "How long have you been playing guitar?"
"Since I was four, and discovered I had a natural aptitude for it."
"How did you originally form Mother Bone Love?"
"When I was 16, I met Jill in school and she introduced me to Lizzy and Gina. We went to the warehouse after school and practiced. And we realized we were a good mix."
"Are you surprised at how much people love your song `The Hidden Feeling'?"
"Nope. Lizzy said she knew that one would be a hit."
The food arrived, and we stopped talking to fill our stomachs. We each paid one-third of the bill plus tip, by mutual agreement.
"Before I decide whether to bind you, we need to all spend a night in bed," Sunny informed me.
I tagged along with Sunny and Sara to their place. Sara took a blood sample from me, then the three of us stripped and climbed onto the large bed.
