 Right now, sex isn't perfect. Women still get pregnant when they don't want to, and they still die in childbirth. Humans are also still at risk for sexually transmitted infections, which have become harder to treat because many diseases are becoming resistant to antibiotics. And the condom? Lots of people would still rather go without. So we still have some stuff to fix. But how, exactly, will sex change in the future? One technology people are excited about is the vaginal ring. A ring that, when inserted in a woman's vagina, would slowly release a hormonal contraceptive and an anti-HIV drug that prevents people from becoming infected. Or we might see the advent of a gel with the same capabilities that women could apply 12 hours before having sex. And for men who want a long-lasting, reversible contraceptive, the future of sex might look like an injection of gold nanoparticles that takes place in the testicles. When heated by an infrared laser, these particles would cause sperm to die, but they wouldn't kill the cells that produce sperm. These futuristic contraceptives don't protect against STIs like gonorrhea or herpes. So what we might actually need to do is find a way to redesign the male condom. Some researchers want to make it easier to put on, wrapping around the penis instead of unfolding over the tip. Or we could use plastics to make them stronger, thinner, and softer. All changes that would also make them more fun to use. The polymers used in these condoms could even release STI-killing drugs when they warm up. The biggest question is whether we'll still want to have sex at all. Virtual technologies like Oculus Rift might one day help couples in long-distance relationships maintain a sex life. Some people think virtual worlds that combine robotic body parts and neural interfaces will one day become as natural and mainstream as the missionary position. With all the danger of swapping bodily fluids, maybe we'll decide it's safer to do everything over the web. But I don't really buy that. Humans are social animals, and sex is one of our most basic desires. We can change the technologies and social customs that surround sex, but the act itself is still the same as it was hundreds of years ago. The next hundred years will change a lot, but sex might be the one thing that stays the same.