We have sex more for connection than for procreation or pleasure.
It turns out that the deep experience of sexual pleasure depends somehow on the presence, and conduct, of others. A brutal illustration of this principle can be found in prostitution. On its face, prostitution is a cold business—the epitome of (mostly male) selfish pleasure seeking. The customer buys physical sexual release for money, plain and simple. But the customer can give himself an orgasm, for free. So why pay? And why is the customer's enjoyment increased if the prostitute produces the sounds of enjoyment and sexual arousal? If the client's
motivation is selfish sexual release, the satisfaction of a biological urge, why does it matter to him if the prostitute is aroused? What excites him about the thought that she is enjoying herself? Fundamental social, interpersonal dynamics are apparently present even here, inside the most alienated transaction.