Unpopular opinion I would say that, there is a good chance, that this situation is “goals”. 1. He’s *chosen* to be a public talker. 2. He moves through his repetition without having a hard, silent block. 3. No *noticeable* secondary behaviors (head Bob, twitch, hand movement) 4. His friend appears to be “anti-mocking” him, and I’m not surprised at all to learn the “mocker” also stutters. 5. Without knowing context, it appears that his initial understandable annoyance quickly turns into a smile of understanding.