Why did God Create Intimacy?

Today's thought: why did God create sexual intimacy? I can't speak for everyone but from my perspective it is something that brings us closer together. It creates a bond between the two of us that is undeniable, and unexplainable without God. Even when I am not necessarily "in the mood" but do it anyways, when it is over my connection to my wife is at an emotional peak. Why did God create it to be that way? To find the answer I thought about it from a backwards perspective. If we look at nature, very few animals pair off as couples and stay that way for life.
If I look at it from the Darwinism perspective of Evolution I would have to ask what is the benefit of it from an evolutionary perspective. It would make sense for the male to sleep with as many women as possible (which some may aspire to) to spread the seed and increase the chances of propagation. For the female staying with one male means stability, safety and a consistent source of food. Both of those give strong reasons for sex to be enjoyable, but does not explain the intense connection that one feels (whether they want to admit to it or not.) That sense of love. If those two reasons were the only reason for sexual intimacy to be more than just sex then the only emotion felt from sex would be joy. For a man, there is no reason that after they spread the seed to stick around with the burden of a pregnant woman and children. They work much better as a team with other men. (Imagine caveman or other ancient men when imagining all of this.)
If looking at it from a Creationism perspective that emotional connection makes more sense. God wants a man and woman to be together, wants us to love and care for each other. It is almost like God is giving us a glimpse of what the rest of the relationship should be like. Lets face it the best (and most powerful) sex is when we are not doing it for ourselves. It is when we are doing it for the other person. When our goal is not self centered within ourselves but outwardly focussed on the other; to give them the most pleasure and make them happy. And the happier they are, the better they feel the better it is for us. If anyone disagrees they have to ask themselves if they have ever had sex with the other person in mind. God does this because it is love. Sex is a way that He is showing us how caring for another is more important than caring for ourselves. That loving another brings us more joy than loving ourselves. God is giving us a lesson. In that lesson we are also being shown by God how much he loves us. He could have made sex nothing more than pleasurable, instead He created it to be much more. He created it with all of the emotional connections that show us just a little of what life can be.