Rainbow, honey, try to look at it from HIS point of view. It's something floating around in his area and he doesn't know what it is or if it might hurt him. (Wouldn't that scare you if you saw something flying around in YOUR room and your didn't know what it was?) If you want to keep the balloon, get it out of that room, out of his sight and put it where he can't see it, or if you're through with it, take it out of the room and pop it so it doesn't scare him. Simple solution. Main thing is - protect him so he's not scared.