I don't think it's a bad thing on your part to want to make sure it's going to work, no. Rather, I think that's a wise decision. I understand where you're coming from though with his facebook...if I had to guess, it's not so much that he didn't ask you (lol in which case, I do agree with other posters) as much as it is that he "advanced" quicker than you're ready. He elevated things into a point that you weren't aware of, so to speak. Is that where you're coming from?

At any rate, no, I don't think wanting to build a friendship first is a bad thing. Just tell him you want to take things slow, and you want to make sure the basis is there before you move on to a full blown relationship. If he's a guy worth your time, he'll understand.

Best of luck!
Harley