1:whatever toi do don't call them a jerk(that would just make them get defensive) 2:stay as calm as toi can 3:make sure toi and your friend are alone when toi tell them 4:give them a example.like toi say" yesterday at lunch toi a dit I was stupid and that hurt my feelings.It would be cool of toi to not say mean things;can toi do that for me?" that is just a example. If your friend is not understanding then I wouldn't hangout with that person much. I hope I helped:)
Like the person above a dit - don't call your friend a "jerk". It'll just start the conversation off badly.
Maybe toi could just tell her how toi feel par how she's been acting. Don't be too straightforward. Be calm. Try not to make her get offended par toi telling why toi think she's being mean to whoever she's being a jerk to. This probably didn't help. :\
I agree with the précédant two, do not call him a jerk. toi could ask if everything is ok? Give some examples of what he's done and maybe mention it's not like them. That way it opens communication. There's a small chance that something is going on with him that toi don't know about. He may be taking it out on toi without knowing about it. But even if that's not the case, it will let him know in a nice way that toi don't like the way toi are being treated. Communication is the key to get to the truth. Good luck,
