When people find out that you stutter very frequently they will try to either play the guessing game with you by trying to guess the next word you'll say in your sentence. Sometimes, they'll even try talk to you in front of people they know aren't kind to special needs people so they call all laugh at you. It's a subconscious way of making people with ADHD feel weak or not normal. I think the best way to deal with people like that is just ignore them and focus your attention on people who will calmly listen to what you have to say.