There is a very fine line between all three. Sarcasm can be very funny. Winding up, or teasing, can also be funny.....but the trick is to know when to do it and when to stop and most people can't do that. If sarcasm and teasing are done at the wrong time or for too long, to the wrong person, they both slip over the edge and become bullying even if the intent in the first place was to just tease somebody. The fact that it's already happening to you means that you haven't done anything about it so it's going to be harder to stop. You have to ignore it. If someone is sarcastic and thinks they're being witty, they want a reaction. They want others to laugh at what they say. If others don't laugh, then they shut up because thinking up witty and sarcastic things is just a waste of time. Likewise teasing. If the teaser gets no end result, no laughs etc. They have to stop doing it. Bullies are insecure people. They bully others to make themselves feel big. If the one being bullied completely ignores them and shows their contempt, eventually the bully will turn elsewhere for someone who is going to give them the attention they crave. Don't smile, don't laugh at their antics, don't cry or show fear. Show either a totally blank face at whatever is said or done or show boredome and contempt and leave the scene as quickly as possible. They will eventually get tired of goading you if they get no feedback at all from you. If the bullying is really bad, then tell a teacher or another adult about it. You might get called a snitch, but that can't be worse than being bullied in the first place. If a person is a bully, he/she will be certain to be bullying other people too. By telling tales on him/her, you will be helping others in the same situation as yourself who will be grateful to you, even if only secretly.
