My partner's penis goes numb 85% of the time, right before he feels the urge to cum, and then he stops totally. It is so frustrating, because I want to know that I am satisfying him, but I feel as though I am wasting his time. He says that right before he cums, his penis' head goes numb, and it goes back in. He is 45 yrs old and has been incarcerated for about 8-10 years, only 9 months ago. He blames it on the fact that he jerked/jerks off alot. Is this true, or am I not good enough to satisfy him to the point of ejaculation? I have succeeded maybe 5 times before, but we've gotten busy almost 20 times or more, so what am I to do. I have even gotten him Enzyte, which he claims only makes him feel faint, so he stopped taking them. I have gotten so frustrated because I love doing it to him.