Why the silence?

I went out with a friend of mine. We've known each other for ten years and were in the same class before. I think we both had crushes on each other, but didn't pursue it back then. So now many years later, we met up and had a first date. It was great and at the end he passionately kissed me. He asked me about sex, but said that I take things slow. So he just put his arms around me and sighed that he could fall asleep like this. It was sweet. He told me that he hadn't gone fast like this in 5-6 years. When we were at the bus stop he said I wonder how it will be when we're together and you're living with your best friend (whom he knows). So he revealed that he was already thinking of us in the future as a couple.

Ok so here's the 'problem'. I had asked him when i would see him next time, and he said next week. So next week arrived and i sent him a text, but he was too busy in the beginning of the weeks with school and work, which i understand. And he told me maybe at the end the week instead. So later I sent him a text about the weekend, but then again he was too busy. He gave me a call explaining that it didn't work out and that he felt bad.
He had to go away on a trip for a week. And i just told him to let me know when he's back.

I haven't heard anything from him. At all. And it's been a week since he came home from the trip.

I'm just wondering for all u guys out there. If a guy is extremely in to you and then doesn't even check in to say hi..

What should I think of this? I have initiated all communication after the first date. And I want him to start talking to me. So i've left the situation be for these 2 weeks.. Haven't heard from him during these 2 weeks.

Help

He could have another someone. Be prepared

Sounds to me like he was after sex, and because he didn't get any, he's no longer interested. Sorry to be harsh, just how I see it.