I don't know how he will react if you say it but one of the things that made me accept my stutter was to figure out the things I can do and what I can't. Being born with this disorder was beyond my control, now that I'm stuck with it and it's consequences, what can I actually do to help myself and lessen the burden? It might sound easy to say but when you have such an issue, you have to be mindful about the thoughts you spend your energy on, don't dwell too much on negative thoughts, celebrate every win and be compassionate towards yourself, be proud of yourself for what you've achieved because even with a stutter, you've lived a better life than many people that set out with less issues. He has a career, friends and a wife, dwelling on what he doesn't have can only hurt what he does have.