I felt really hurt and betrayed today, and what should I do?

Well Today, when I was in Class I was in a 3-Person Group, and one of the Guys in the Group was acting all Grumpy and Tired, and then he called me Dumb and said that "The Smart People always get stuck with the Dumb People" and it hurt my feelings.And then he kept saying that I was copying off his Paper, and I wasn't. Then a Few Minutes later, he started acting nice to me, until he saw my Paper and then got mad at me again.And then a Few minutes later, he starts being nice to me again.Then later, We were sitting at a Table at lunch and he told me to prevent someone from sitting at the Table, and when I didn't, he got mad at me again.And then when I asked if he had anything That I could have, He got mad at me and looked at me and said "Can you clearly not see that I'm eating something different!?" And after that, He started telling everyone what I did and then he didn't say anything else to me.Later at the end of the day, I had walked up behind him, and then after a Long Time, he turned around and saw me and got mad at me again! He said "I didn't know you were standing right there, I've been standing here for 20 Minutes, and I didn't even see you!" But I'm really not sure if he was being mean or sarcastic. Then, this little short guy got mad at me when I said that This Kid was a Bus Rider.He said "No He's Not! He's a Car Rider!" And then I tried to explain to him that I think he was a Bus Rider just that One day, but He would not Listen to me.I don't know what to do, all I know is that It hurt my feelings and what should I do?
Asked Sep 01, 2015

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