There’s no easy answer to be honest. You can try doing it through layers of clothes or doing stuff that feels good but can’t make you cum.
However ultimately only one thing is really going to solve it – self-control
One can have no smaller or greater mastery than mastery of oneself.— Leonardo da Vinci
What’s so positive about this kink is the fact it requires you to develop self-control; which is one of the most important personality traits you can have in order to be successful in life. So how awesome is it that something so sexy and kinky can help you with that!
Try REALLY hard to just stop, even if you just use your curiosity to motivate you. Once you find out how good it feels to stay horny and wet, and NOT cum, it’ll start to become easier to give up the short term pleasure of an orgasm in return for the day-long arousal and ‘high’ that being denied can give you.