Bro, if you really want to de-sensitize a bit, don’t use that expensive leg numbing gel! 5-10 minutes or so before your gig, spray about 3 or 4 good shots of chloraseptic all over the old glans. Let it set a few minutes then wipe off. It won’t numb your gal, won’t burn, won’t stink and won’t numb you to the point you can’t feel your legs. Not to mention that it’s cheap and not embarrassing to buy.
All my buddies in the good old USMC used it with hookers to get their moneys worth. I have turned other guys here onto it over the years and they have had great results. In the meantime, work on control. Recognizing your breathing patterns and your PNR (point of no return) is critical! I don’t have especially strong muscle control, but cum when I’m ready to cum because I know these two simple things.