The pleasure we get from sex is largely due to the release of dopamine, a neurotransmitter that activates the reward center of the brain. More dopamine means more pleasure, and the stimulation leading up to orgasm causes an intense flood of it. Unfortunately, in men the orgasm itself releases dopamine suppressors, abruptly halting the pleasure and forcing him down from his high.
Edging:
Your goal is to pump his brain full of as much sweet dopamine as you can, but an orgasm gets in the way of that. Edging is an effective tool to get around this. Edging is the act of pleasuring a guy up to the point of orgasm, but not allowing him to cum. After a brief period to cool down from the brink, he is then ready to repeat. This cycle of teasing and denying him compounds his sexual arousal. A man resting on the edge but not allowed to cum is much more receptive to less conventional forms of stimulation in a desperate attempt to achieve some feeling of sexual satisfaction and continue riding his high.
Ruined orgasm:
The act of edging always runs the risk of your man going over. If this unfortunate occurrence ever happens, he only has himself to blame, and the only proper recourse is to ruin it. To ruin an orgasm is to stop stimulating a guy as soon as he starts to cum. Without the continued stimulation, there is nothing the man can do but pump his pelvic muscles in a desperate attempt to get some satisfaction from the act. His penis simply bobs up and down, leaking cum. The amount of dopamine suppressors released is significantly reduced in this case. The resulting orgasm is very unfulfilling, more or less negating the act and leaving him with nothing to show for it but a load of cum for you to use at your discretion...
Cum play:
This involves forcing him to play with, even eat his own cum. Think about it. He has shot his load so many times in his lifetime. He loves getting it in your face, on your tits, on your ass. He wants you to swallow, to play with it, to beg for it! Don't tell me he isn't a little curious about the taste? The feel? He has been taught to think that cum is "icky" for him, but "yummy" for you. This mental block is the only thing that is stopping him from finding the same intense sexual arousal in being forced to play with his cum that he gets from watching you play with it. It is your responsibility to overcome this stigma, break down the mental bock, and keep his sexual high going after having his orgasm ruined :)