numbing gel or cream can be a denied boy's most valuable asset during training. if the urge to cum gets too be too much for him, he can simply rub a little lidocaine gel on his cock and the choice will be made for him. he shouldn't be able to feel a thing, much less cum.
it can also be very useful when you're using his holes. if you want to use your cum-dump but don't want him to be pushed to an orgasm, rub numbing gel on his cunt while you use his asshole, or simply use his numbed cunt. be sure to remind him throughout that his holes are there for your pleasure, not his. remind him while you use him that he is serving his purpose, which of course is to spread his legs and offer you the holes between them. his pleasure is not necessary for him to serve his purpose, and orgasm is especially unnecessary. keeping him denied is a great way to ensure that he is always eager to have you use the fleshlights he carries between his thighs.