is it wrong for people to make fun of you for having diabetes?!

Depends on what they do. If it's bullying then yes it's wrong but if it's just a joke then learn how to just laugh with them. There is nothing worse than a person who just can't laugh at a joke. Really the only people you shouldn't joke with are psychopaths and depressed people since one will kill you and the other would probably take it too personally.

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Making fun and laughing with is not different. If you make a joke about something you are making fun of that thing. Hence making fun of. It is not childish at all unless it's bullying. It's called having a sense of humor.

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Seriously people. I bet you guys make fat jokes and laugh at them too. This is no different. You know what I find funny. The same people who say it's wrong actually do laugh at other people's conditions when put in a humorous context. So they are being hypocritical.

It is wrong. The behaviour is childish, ignorant, immature, unpleasant behaviour. You could tell them that, or simply "Grow up."

Making fun OF you is not the same as laughing WITH you. The former makes you a target (not good) whereas the latter is designed to cheer you up (nice).

Don't let them bother you, they're dumb.

Ofcourse it is wrong to tease a person about a medical condition.

Yeah it is thats just messed up.

yes it is and who ever should be a shame of them selves

No