Chastity and orgasm denial discussion

Hello I was curious to know if a chastity belt might assist me in reaching my somewhat unique objective? My wife and I have discovered an entirely new realm of prostate stimulation for me, something we hadn’t experimented with previously. We both really enjoy it now; everything is wonderful and entertaining, but here is the situation. When she begins licking and kissing etc., I tend to ejaculate very quickly. Usually I would request her NOT to touch my penis and focus on my testicles and anus to extend the pleasure, yet even a slight stroke from her against my cock results in me finishing!! I would LOVE to discover a method to control my orgasm and considered trying one of those chastity gadgets but wasn’t certain if they work with a completely erect penis? If not, what other gadget can be used essentially to lock up my cock so she won’t feel the urge to touch it? This might sound crazy, but I don’t want to ejaculate! Or said differently, not THAT quickly! Please HELP.