I need your advice in a major way, I just can't seem to get up the nerve to ask this guy what he's

thinking! I've been seeing him for (yes) 8 months! I started seeing him straight out of a relationship where my heart was broken. I guess it was somewhat of a rebound thing at first, but has grown into much more -- for me.
Basically (in the beginning) due to my heart break and paranoia I was keeping him at a distance...seeing him maybe once a week.
Well the situation has remained the same...like we've just made it that and now I'd like more. He has told me on more than one occasion that he was looking for something 'serious' to which I gave no reply.
The thing is, is that outside of the 'serious' comment, he doesn't put much effort forth. Like he doesn't call me during the week (we usually go out on fri/sat) or really check in at all until it is time to call me up and ask me out for a date which usually consists of dinner/movie/show, etc. and a sleepover.
I am dying to bring up the "what are we, do you want more" conversation but every single weekend I chicken out! It's just that when we're together it feels natural and good.
I haven't even asked the man if he is dating or sleeping with anyone else! I assume he isn't, but you never know.
Plus, I recently found out about a 4 month trip he is planning on taking in the fall. OK.
He has said a least three times to me that he wants a serious relationship and that he is over the whole dating thing for sure.

Two questions, please,
What does it seem like he is thinking, I mean why does he not call me during the week?? And IF he wants to know what I want why doesn't he just ask?

Girls, have you ever been in this situation where you just didn't have the nerve to 'talk to the guy" and if you did, I would love some suggestions on how to go about it!

Thanks!
BTW, he is 43 if that makes any difference.