Some people use laughter when something happens they don't understand. Most adults will quickly pick up on someone stuttering and that's what counts. If they continue to laugh at you knowing you have a stutter, well, that's something on them but what you do about it is important. How you react can change your life. Are you going to cringe with self-loathing, shame and embarrassment or are you going to get over it quickly and get on with life. Up to you.