My son felt the same way about neutering his Staffordshire bull terrier. I have been on him and on hiim. Now 3 and a half years later, he realizes his dog is getting too aggressive. He finally talked to his vet about it. The vet said he doesn't like to guilt people into doing it, but honestly your dog has a better chance of living a longer healthier life by having him neutered. He toldmy son thatin many cases of dogs getting diseases they would not have gotten them had they been neutered.
So my adviceto you is have him go with you to the vet next time(you know MEN-they think we know nothing sometimes)
Or you can research all the health benefits and put it in the bathroom for his leisurely reading material.
Good-luck!