even when love hurts dont people still fall in love

no, people procreate because it's fun

No, that is why it has evolved as being about the most pleasing physical act sexually reproductive creatures can do.

Yes, because at least some people would think it was their duty to carry on the human race. However, the population would decline fairly swiftly, and there is a significant danger that it would decline from generation to generation until eventually there would not be enough of a population to reproduce the next generation after taking into account consanguinity, geographic distance, some women being infertile, &c. Chevalier Daniel C. Boyer

Well, giving birth isn't exactly a cake walk, but women still get pregnant anyway. I think it's just encoded in our DNA to know to reproduce.

Food, sleep and sexual urge are basic instincts built into the genes of all living beings. The urge for continuation of speices comes from the subconscious mind. People can not resist it even if it is painful. "Perhaps the most universal instinct living creatures possess is the one which drives them to reproduce, to perpetuate their genes. It is surprising just how much sexual activity in the wild is made up of rituals which humans would generally consider painful or cruel. There are many examples of animals which vigorously bite into each other during intercourse (the females take the brunt of this practice), or which link up in other not-so-pleasant ways. The mating of dragonflies is fraught with complexity and discomfort. The male first grasps the thorax of the female with his legs, he then flexes his abdomen forward and affixes two claspers to the female. In some species a sticky secretion bonds the pair together as well. Then they fly off together, mating in mid-air. Clasping before marriage is frowned upon in the wild, incidentally. Mother dragonflies are often heard to say: "You should be ashamed of yourself, clasping with every Coenagriidae you meet. In my day, we never let a man grasp our thorax, at least not until he was introduced to our parents." One of the oddest practices in the mating world belongs to a breed of fly. Its technical name is Serromyia femorata. The flies take up a position during sex which resembles kissing, but at the end of mating, the female sucks out the body content of the male through the mouth. So, what we've heard is apparently true. When it comes to a mate, it's what's on the inside that counts. Ants, too, have a strange mating ritual. It seems both the queen ant (female) and the prince (male) have wings, and when the mating urge hits--generally after consuming a number of imported beers--they fly 100 feet into the air, have a brief copulation, then the male's wings fall off and he dies. The female goes on to lay eggs resulting from that brief encounter for a period which can last up to 15 years. ("Doctor hurry, it's almost time, the contractions are coming six years apart now.") Female ants must surely be hoarse from all the screaming. Just about everyone has heard that the female praying mantis eats the head of its mate after sex. But were you aware that often the female mantis will consume its mate's head during sex? Shockingly, this doesn't deter the male from finishing what he's begun. That's right. If the male mantis has mounted the female before she begins to devour his head, he will successfully complete copulation without it. Most women have always suspected this would be the case with their human counterparts as well. The sexual practices of animals are almost as varied as our own. Porpoises often participate in group sex. Roman snails have been observed performing foreplay. Many fish seem to enjoy kissing as part of the mating ritual. It is believed that deer masturbate during the rutting season by stimulating their antlers. There seems to be no end to the variation. And all without the aid of manuals or how-to videos. Just instinct. All of this serves to remind us that although we fret and complain about our sex lives, we should keep in mind that in many ways we've got it easy. It should also keep us a bit more humble. For while we take a lot of pride in our sexual sophistication, it is useful to keep in mind that there are creatures around who have been doing it faster, longer, more often and even, on occasion, without their heads. http://www.dribbleglass.com/articles/animal-kingdom.htm Painful Sex Still a Painful Secret (but people continue to have) Women who suffer from chronic painful sex often have stories that seem 60 years out of date: stories of secrets, of fear, of ignorance, of condescending doctors and foolish sex advice. Instead of sex that feels good, women report "a stinging, a stretching," or say it feels "like something too big coming out of something too small" or "like it's ripping you apart." While the pain is horrible, struggling to find treatment may be worse. Even top gynecologists agree that training on chronic sexual pain is minimal. http://abcnews.go.com/Health/PainManagement/story?id=4320372&page=1