Re: When to have "The Talk"?
I think, instead of "asking him" to communicate his feelings or his perception of your relationship and what it means (guys usually are really not good at that sort of thing), you should just tell him how you feel.
Just say, you know... "Look, I've really been enjoying your company these past months. I really have fun when we're hanging out together, and the sex is awesome. I love what we have, but I'm kind of starting to want more, because my feelings for you are growing stronger."
Just see what he has to say to that. I mean, he'll either say yes or no, and then, either way, you'll know where you stand.
Best of luck!