If you look far enough in to the future, then all kinds of things will be possible in all kinds of ways, but I think a more interesting discussion is what advancments in PE will be made in the NEAR future. It seems pointless talking about what PE will be like in a thousand or more years time because we will be so scientifically advanced as a species that penises and vaginas won’t be used for pleasure or even procreation. Penis size will be of complete irrelevance because the penis will be of complete irrelevance. Men and women, will probably have computer chips in their brains, enabling them to have complete control over their minds and be sexually stimulated and satisfied by a mere thought. They might have display screens that apear in their mind’s eye, allowing them to choose what to do with their brains. The sub menu might be filled with all kinds of things. Attached to a cyber space portal in which any experience you wish to have is available. The closest description would be like the matrix in the film “The Matrix”, except being considerably more advanced than even that in capabilities and applications..
We would also have been geneticly modified. We may not have genitals any more. Our brains may be designed completely differently. All primitive desires may have been deprogrammed due to their irrelevant status in such a new world. Women won’t want a big dick, they won’t want a dick period. They won’t think about it, they won’t crotch watch, they won’t need a good stretching and filling up. They might not even have vaginas and the human penis may not even exsist. Men won’t have the slightest interest in a woman’s breasts, which probably don’t exsist anymore anyway. Get the picture? We will be creatures of cyberspace and outerspace, evolved and involved in worlds within worlds, within worlds.
So, with the penis and therefore PE being irrelevant in the distant future, the only way to look at PE’s future is in the short term future. Centuries not millenia. Certainly not eons.
The next breakthrough in PE, accepted by the scientifc and medical community? That will probably be stem cell technology, but who knows?