My Bf Acts Nice Then Mean (i mean MEAN)Help!?

Hi, my bf is very special to me but he acts really jerky to me some days. Like mostly at school. Like i hugged him and kissed him on the cheek, and he said "not in school, thats one of my rules" and i have this BEST BEST FRIEND her nickname is bean, and she has a special arm on him. and im not even allowed to touch that arm, so he says " dont hook arms with this one, its bean's arm, thats another rule if mine but use the geust arm" SERIOUSLY! and of course he hugs bre first and me second (sometimes, i always have to ask becase bean is first :( ) i need advice