I like that you're asking this question. I think it's normal to feel uncomfortable, having a stutter is definitely discriminated against. Having a speech impediment is something people find uncomfortable in others. It's ableism, I mean, disabled people have speech impediments, right? But we can't help it. We speak fluently in our heads and then it doesn't come out. It's really very frustrating. I'm an extrovert, but having a stutter has made me live an introvert and sometimes anxious life. So many opportunities gone by. Don't get me wrong, I think many people with a stutter make something of themselves, and I did too. But it's probably not what they had done, were they not stuttering. People's reactions are one thing, the ability to speak another. I mean, it's nice the guests *would* give me time to give a speech at my friend's wedding, if I can't get it out it's no use. So I don't give the speech. It's also quite rare to ever really get rid of it. It can often be managed, but once adults, people usually have this for life. Don't ask him why he stuttered in this occasion or on this word. It just happens. He's probably ashamed of it and you pointing it out makes it worse and more likely to happen around you. Also, it just happens, we don't know why. If he doesn't stutter much around you, that's a really good sign, it means he is comfortable. It's really worth something to not stutter much around a person and it says something about you. I'm on the fence if I should suggest you ask if he would prefer you take over if it happens in public. I would prefer that But many people feel very strongly about this. I would suggest to definitely not do it without asking.