Now if you only stutter at presentations, that happens to everyone, dont worry. But if you have stuttering normally too, that may be a problem. Laughing it off isnt a very nice way of handling it. Even if you dont think that it hurts you, it still does. Just tell them that you sometimes stutter and they shouldnt laugh about it. Before your presentation, tell everyone that you may stutter. That way, they will be prepared and you wont get anxious about them noticing it.