I barely masturbate, so no. Masturbation is unrelated to stuttering but the unhealthy consequences can lead to more stuttering. Masturbation is basically a biologically-created drug, and it is used to relieve stress or sexually explore yourself. However, porn addiction and unhealthy fapping can be really bad both psychologically and emotionally. Only masturbate in moderation (once every 3 days is what I recommend) By watching pornography or even animated porn (such as hentai) constantly, you'll start to desensitize yourself and your views about the opposite sex. You'll become more afraid and scared of communicating with the opposite sex even more because you focus on their body instead of them as a person. And when you're afraid, you'll stutter more. If you are suffering from porn addiction, join programs, receive help, and step up with your self discipline to eventually stop.