Personally, I like the CB-2000 the best out of any technique or device. Of course, I'm sadistic, too. The fact that I sell it on my site is secondary, as there are other things that I could carry and have chosen not to. When I was professional, I would make my long time clients come by countdown. I'd tease and torment, and tell them they had until ten to come or they couldn't come at all. Orgasm denial or control is 99 percent mental and takes a lot of training and patience. There are physical things, such as rings, that can make it much more difficult for a man to come, while maintaining an erection. There are creams that prolong erection by numbing sensation. They are generally designed to prolong erection, but can also take away enough sensitivity to make orgasm next to impossible. Other than that, the obvious is to simply not let him have an orgasm. If he's used to coming a lot, you'll have to make sure that you taper down, as total denial can cause a severe case of 'blue balls'. While I've never actually seen balls that had turned blue (except when I waxed them with a blue candle, that is), it is extremely painful for a man that is used to coming to be denied for days. Be sure you have lots of communication and it could be a lot of fun.