Here's a thought...What would society look like if:
Humanity could only have ONE orgasm in their entire life. If it's wasted in a silly meaningless way, it's gone for good. The male and female would feel 1 thousand times as good however, the orgasm mind-blowing and lasting for the entire day, ever cell feeling unimaginable joy while the brain feels pure uncontrolled joy, every molecule of serotonin soaking deep as for the entire day you feel incredible pleasure beyond all reason.....until it's over.
What would the world look like with that kind of sexual limitation? Would relationships survive? How does one hold back for the "special" person? If deciding to release solo, how would one prepare for the once-in-a-lifetime event? etc...
Ooh I love hypotheticals! Here's my guess.
So, humans would need to have developed in a significantly different way for this to be possible.
Firstly, men would need to have a completely different sexual drive, otherwise they'd probably masturbate their way to infertility not long after they hit puberty.
Secondly, female fertility would need to be higher. Relatively few couplings actually result in pregnancy and, especially before modern medical science came along, many more of those pregnancies ended in tragedy. Women would therefore also need to produce children in large litters - even ten at a time probably wouldn't be enough to maintain a breeding population. Men would likely need to instinctively know when a woman was ovulating too, or ovulation would need to be close to constant (which would be a massive drain on resources and require significant changes to the menstrual cycle).
Thirdly, there'd need to be more males around than females. A woman does not need to orgasm to become pregnant.
I can't see the human species surviving otherwise.
Relationships, evolutionarily speaking, are not just about reproduction. If the male could only breed once, they would be strongly incentivised to take care of any offspring that they did manage to produce. The female would still find it very useful to have a non-pregnant person around to help out during her pregnancy. I'd therefore say that relationships would be much stronger, at least until the offspring reached college age. In fact, while there would be no sexual impetus for a male to stay with a female, there would also be no reason for him to go looking for a new mate either. Therefore, male infidelity would be almost nonexistent and female infidelity would be significantly higher and much less stigmatised, since people would know that it wasn't about lust or sexual attraction but about a woman having a second chance at reproduction. Male infidelity, on the other hand, would be a capital crime.
In fact, it wouldn't be surprising if men were to become sexually non-jealous and form male 'harems' for a single female rather than a 'traditional' family unit, since having more providers around would benefit everybody's offspring.
All that being said, it's worth noting that in some species that famously do breed only once - i.e. social bees - the male dies soon after mating anyway. For a male bee, part of sex is ripping your own dick and organs out to plug up the queen's lady hole so she can't have sex with anyone else! Ow.
