Dead people live again only when some descendant is having sexual intercourse. Ancestors can talk with each other during the act, but the living have no clue. Then Adam dies and can talk to his living descendants. There are interesting implications.
A man snatches a 13-year-old girl from the corridor of a hotel right outside his room. He toys with her as he works up to rape and impregnation. It would be despicable as reality. But as fantasy -- well, as fantasy, enjoy!
In a near future, DNA sequencing allows an accurate image of the future human based only on the genes in a fertilized egg. And a simple scan by a smart phone can determine the exact genetic sequence that a man or woman would contribute to a baby just then. Any man and woman meeting casually can visualize with great accuracy the baby they could create if they had sex. What would happen? What are the implications of seeing a person you could create?
Nature presents us with an amazing variety of animals with an amazing variety of life stories. All of them have sex, some way or other. Here are the sexy little stories of humans who have sex the way some species or other does it. Caution!
A Calamity has wiped out most of the population. A few powerful men run each surviving nation. They want to repopulate the world quickly, and for that purpose they need a reproduction rate above what the women would choose. Using some clever bits of genetic engineering, the ruling men compel women to do their bidding in the realm of sex and reproduction, without threat or force.
A disease suddenly descends on humanity. Women develop a serious illness which can only be cured by sexual intercourse, and it has to be with the right guy. No condoms, no pulling out, and he has to really want it. Bad luck? A sign from a God with most mysterious ways? Or could it possibly have been designed by a human with an agenda?
Blessed Leader rules his land with an iron fist. His lust is strong, and he tries to impregnate two girls a day. But he wants his sexual prowess to be more widely appreciated. He finds a way to mate with thousands of his subjects at once.
Humanity has a different and peculiar sexual structure. Sex might make a couple form a bond, which means they share in each other's feelings and thoughts, enhancing sex and creating a sense of closeness. Everyone needs one bond, but no one can have more than two. If your mate has a bad secret, a bond can be painful. The story explores the resulting complexities.