I highly recommended this article,Casual sex is a con. Here is a quote...
And here is her blog...The Dawn Patrol
But in all that casual sex, there was one moment I learnt to dread more than any other. I dreaded it not out of fear that the sex would be bad, but out of fear that it would be good. If the sex was good, then, even if I knew in my heart that the relationship wouldn’t work, I would still feel as though the act had bonded me with my sex partner in a deeper way than we had been bonded before. It’s in the nature of sex to awaken deep emotions within us, emotions that are unwelcome when one is trying to keep it light.
On such nights the worst moment was when it was all over. Suddenly I was jarred back to earth. Then I’d lie back and feel bereft. He would still be there, and if I was really lucky, he’d lie down next to me. Yet, I couldn’t help feeling like the spell had been broken. We could nuzzle or giggle or we could fall asleep in each other’s arms but I knew it was play acting and so did he. We weren’t really intimate — it had just been a game. The circus had left town.