If that is a joke then accept the joke unless you also dont give a joke about them. Bullying is just normal for a close friends but one the bullying becomes severe then you should decide as soon as possible before it gets worse
It is worse right now. This happens to me everyday but I kept ignoring them by just laughing but the real thing is it hurts so much that they don't even know.
Are you being emotionally hurt or are they also trying to hurt you physically as well? Then i guess you should have to isolate your self and separate from them. You know what mate if you are living in those persons that doesnt make you feel happy and contented at life then you should find another one. I also has a few friends in my circle because i only choose the ones that are best for me but it also doesnt mean that i wont be interacting with them