People hardly react at all - mine is quite mild, and I have many strategies for managing it, so there are numerous people who might not even know I have a stutter. When people do, they usually don't react at all (which for me is nice). Sometimes (rarely) people give me a confused or an "it's okay" look, which isn't their fault, they are taken by surprise, but personally I don't like that. Very rarely (like once or twice a year) people will finish my sentence or word for me, which I don't know how I feel about, I suppose it depends on the situation. Sometimes it can be a valve (if it's a bad "episode'), but mostly I don't like it; my parents or family never did that growing up, my best friends, or my wife never does that now, so I feel like they are inserting themselves in and giving themselves the right to speak for me. If they do react in either way I usually try to say "Yeah, I have a bit of a stutter, which can creep up at times" (and I try to never apologize) which just melts it away. Sometimes you don't really have a chance - if you're ordering something in a coffee shop for example, you just have to let it go! On the extremely rare occasion (like maybe 5 times in my adult life) that someone makes a joke, which is usually when they don't know and just think I'm stumbling over a word, I just say "I have a stutter, and sometimes it can be difficult for me to get certain words of phrases out" and they instantly feel like an asshole and most often apologize. I'd echo the sentiments of others, that mocking or laughing disappears as a you get older. When I was really young, other kids would make a joke, just because they didn't get it. By the time I got to high school pretty much no one said a word, it wasn't a big deal. Then college, it wasn't even an issue, and then in the world of work it's pretty much the same. I do note that mine is quite mild, and usually pretty well managed, and so others will have a different experience.