OK, then. A quickie post before heading to work...
Listen to Corey and GASlick; odds are good that any break in the routine is going to be the end of it.
You can't take this personally, it happens all the time and in many different kinds of scenes.
I can personally share your frustration, though, not that it helps much to resolve the situation.
There are two dudes I know at a certain cruising spot, but unfortunately for me this place is thirty miles from my home. I have made suggestions to both of these dudes that should they ever wish to come to my place we can have privacy, safety, and plenty of time with no interruptions. They haven't taken me up on the offer, but then again... very few dudes are going to drive thirty miles. Me personally... I WOULD drive thirty miles for safety and privacy, but lots of men get off on the risk, the anonymity, or just the entire scene.
One of these two guys has never, EVER spoken a single word to me. He sucks my dick, makes happy noises as he does it, listens to ME talk, but won't say anything himself. Most of the time he gets me off, but now and then, if I seem to have a bad feeling about possible traffic in the place where we are, I will cut things short if my nervousness is preventing me from having a good time. The dude doesn't seem bothered by this at all, though. He has a cool habit of kissing my dick gently as if saying "see ya next time," just before I zip up, whether I've cum or not. And there always IS a next time. This has been going on for three years now. At one point, I hadn't seen the dude in six or seven months, but we certainly never forgot about each other and sooner or later I ran into him again.
Just recently I was in an area NEAR this location, but not at the location itself. I stopped at a public restroom to take a leak (a REAL leak, I wasn't cruising in the restroom, nothing goes on there). Yet the same little dude suddenly walked in and surprised me. He just got onto his knees immediately and sucked me off. I was so taken aback and turned on by it, not having had restroom sex in a LONG time and not expecting it, that we lasted all of five minutes. But it was hot just the same, and he still gave my dick that little kiss before he left.
This other dude I know... well, I like him quite a bit, at least as far as sex goes. Until recently, we may have said a few quick words to each other, but we never really talked at length. We had this little routine going and we rarely deviated from it. Mostly he sucked me, but I like his dick so sometimes I'd blow him for a while, too. Problem is, sucking dick isn't my strong suit, at least not with him: he's one of these face-fucker guys and I don't like that very much. Additionally, though his dick isn't very large, it's angled enough so that he chokes me. This ruins it for me, so I prefer to let him do the sucking.
Then suddenly he started talking to me at a time when we weren't screwing around because other people were there. I didn't mind this, since it turns out he's a nice guy and we had a cool conversation covering various random topics as well as the usual "cruising tips" swap. We didn't mess around that night, but he had said to me that he doesn't come to this place to make friends because once you are friends, you seldom get to fool around with the guy -- it feels awkward. I agreed with that and said to him upon leaving that we could be buddies and he could still suck my dick. He said something like: "Love to suck that nice dick of yours anytime."
So that was cool, and I went away happy. I'd also been meeting this second guy for about three years, too, I should mention. So I run into him again two nights later and we talked just a little bit more, though not to the extent that we did previously. We set about to messing around and... it just was terribly OFF. He didn't do his usual excellent job of sucking me that he usually does, so I decided I'd give him something instead. But he seemed uptight that he kept making me choke. My thought: well, then... STOP choking me, I'm not enjoying it! So then he gives me the old "take a raincheck" line and the standard: "I'm really tired tonight" line. Those are MY LINES!
The long conversation we'd have before seemed to be the death of the hot fun. Maybe that will change in the future, but I haven't been back there in a while.
The kind of anonymous familiarity you described is similar to my own anonymous familiarity with these two dudes. It's great to KNOW someone is interested, to have established a hot time together and repeat that often. But sometimes, if you take it to a new level, forget it. You have to let guys remain within their comfort zone.
But I suppose it wouldn't be fair to tell you FOR SURE that you wouldn't have any future chances with this guy if you said something to him. YOU MIGHT -- but in doing so, you have to accept that you are taking a risk of blowing it.
Is it worth that? Do you think that if rejected you could go back to the same bookstore scene, not mention it again, and still get the guy? Or would he maybe be so worried that you'd pressure him for more each and every time that he would stop messing with you completely?
Decisions, decisions...
The fact is, sometimes I've had success being able to establish an anonymous relationship with a fellow cruiser which extends a LITTLE bit outside of the cruising scene. So I'd be lying if I told you that it is impossible. But to be honest... it ain't easy.
I DO have several anonymous type relationships with buddies who come to my place on a more or less regular basis -- we have our fun, share in some limited conversation, then say goodbye until the next time. But these all STARTED here at my place. THIS is the cruising spot, so to speak. There has never been the need to make a transition or violate anyone's comfort level.
Finally, in my youth, I tried a few times to make deeper contacts with a few guys in some not-so subtle ways. One that comes to mind was when I left a note on a dude's car -- and found out several years later, after the fact, that his lover at the time had been the one to find it! This is a great story, actually, but not time to tell it now. Passing notes is a BAD idea. A dude once left a note on MY car about a year after I did that to the dude I liked -- and a gal I worked with almost found it (I had asked her to move my car from the parking lot, but luckily did it myself).
The moral is: you have to respect limits and privacy.
The ONLY way I can really think to do this if you want to risk it and push the envelope is to maybe casually mention it while you're screwing around, in a sort of hypothetical way: "I wish I had your dick in my mouth back at my apartment a few blocks from here so I could blow you for hours." No real response is necessary here provided you SHUT UP after that and just get back into the sex immediately. It's OUT there and he can make the next move if he so desires. I would NOT mention it more than once.
But I think it's probably best not to mention it at all, though the choice is yours. It sucks because you COULD have something really great and fulfill a fantasy -- or you could ruin everything.