Whoo, monster post ahoy! I'm going for the pulitzer!
I think one of the most exhilerating parts of having someone do t&d with you is the fact that you aren't entirely in control any more. Sure, you can tease yourself when you're alone, but sooner or later, a guy gets to that point, and it's different for everyone, but everyone has a point at which their willpower crumbles, and they either have to stop or cum. So really, as long as he's doing it to himself, he's not
really teasing himself, at least not nearly as much as you can.
So, I'd recommend playing that up. Really sink home that you're in control. Try tying him up, and especially, blindfolding him. Then, when he can't see you (and you might want to add earplugs so he really can't tell what's going on), don't just go at him. Play with him for a minute, then take a minute off. If you really work him up into a frenzy, then go get a drink or something and come back, or work on him in short bursts, he'll have no idea what's coming next. It's one of the tricks people try to make themselves feel in control of a situation even if they're not: they try and anticipate. As long as you are doing what he expects, he'll feel perfectly content in the knowledge that he can predict your next move, and he's okay with that. It's safe. Once that's gone, he has no idea what's coming next, and that ought to really ramp up the intensity for him.
Of course, nothing works for everybody, and you won't get the best out of your sessions until he manages to tell you what he wants, but some other ideas are to experiment with various textures and fabrics, like silk and feathers, and to keep changing up whatever methods you're using on him. Again, I encourage you to mess with his expectations, so he never feels like he can anticipate your moves, which will in turn stave off feelings of boredom and repetition. Pay attention to what you do and how you do it next time you tease him: Do you start off slowly and work up to the edge gradualy and sensually, like foreplay, or do you whip him into a frenzy from the word go? Once you get him to the edge, do you make him leave himself alone and calm down, only to drive him berserk again, or do you try to set a new record for how long you can keep him there. Is there any predictable pattern to whether you let him cum at the end, perhaps based on how long it's last been? Do you ever mix teasing with regular sex?
If you haven't tried these, consider using randomizers, like dice, to determine various things, or seeing just how long he can handle the denial before he HAS to cum (the answer: probably longer than he thinks. If you haven't, try it and see. You may need to work up to longer periods of denial over time, but you could be amazed at how eager to please you he may become, and when it's over, his orgasm will probably be mind blowing.) One simple but excellent game that is one of my favorites is to get him to the edge, have him stroke himself, and tell him that he's not to cum until you tell him, but when you do, he only has a few seconds to do so. Ergo, he pretty much has to keep himself on the edge constantly, and he'll find walking that razor thin line between cumming before hand, or dropping too far away to make it in time, even worse when he's stroking himself; feeling like he ought to be in control (after all, it's his hand!), but he's not.
It is important, though, I think, to make clear that there should be some penalty for cumming prematurely, or that if he doesn't cum when you tell him, he doesn't get to. If, in the end, he feels like he can still cum any time he wants to, even if you don't let him, a lot of the exitement and anticipation will be gone. If he can't handle that, and wants to ensure he gets a "happy ending", then I'd recommend sticking with games where you directly control his orgasm. I'd say the two most likely reasons he likes t&d are either: the idea of having you in command, which might be something he has difficulty expressing, especially if he enjoys it as a fantasy, but not as a lifestyle, and is concerned that if he tells you, you might try and become a domineering bitch (no offense) in all aspects of your relationship (Then again, maybe that
is his fantasy...which would also be difficult for him to express. Tread lightly, and make sure he understands you just want to learn more about him, not judge him on anything, and he ought to open up to you if he feels safe. If that fails, get him on the edge and ask again :)
Secondly, he might not be so interested in the domme/sub aspects, but simply enjoying the fact that t&d increases the pleasure of your orgasm. If this is the case, then get his permission at the beginning of the evening, and go to town. With you edging him, he can be taken so much farther than he could on his own, and he can be allowed to linger on the edge for so much longer than his self-control would allow. Try just setting aside an evening, and going to town for as long as you like, using as many different methods and items as you can think of, but mainly, just keeping him close to orgasm. By the time the night is through, he should be making some pretty interesting noises
Hope I've given you something to think about, and I wish you and your man all the best. If you're still loking for ideas, try looking around on the internet for t&d stories and video clips (or go through his history, if you're okay with that, and see what it is that he's found so interesting)...there's some very creative stuff out there. In the end, you're the fantasy of a lot of guys out there, and I'm sure you and your boyfriend will have some wonderful times.
Enjoy!