It sounds like reflex to me and a not particularly bad "phobia" to have if you want to call it that. Sounds like you can be around balloons though but don't like them versus run from/avoid them. Either that or my husband has a phobia of broccoli I don't particularly care for the sudden, out-of-my-control, popping either. Nice son! Just make sure he doesn't become "afraid" of them because you are?