Let's do the easy part first. You went on a holiday together, had a lot of sex, enjoyed it, and enjoyed the holiday. So that was good.
The next part is easy too. He did this because he found you attractive, pretty good in bed, and fun. He enjoyed screwing you and you seemed to enjoy screwing him. Everything seemed good.
Now we get to expectations. You were expecting that he would find how much fun you are and decide that he couldn't live without you. He was expecting you to be this months sex partner, where you have a good time, and want to repeat as as often as you could.
But sometime during the week, between sex and dinner, or dinner and sex, you let it slip that you didn't think that just being fucked was what you wanted out of life. He made note of that and started disengageing from you as soon as he could. You ask for a relationship, he ran.