Girl help!?!?! i guess boys too?

my boyfriend is acting so different... like last night he was acting wierd it was our aniversary last nightt && he was kinda a jerk... he was hugging other girls and letting them be smeeling him and stuff and it bothered me....i dont know why he was acting liek this... maybe it was because my brothers were there too for a little while but his friend max whenever he would come by he would act jerkier. when him and i were alone we madeout and everything was fine. i dont understand this??? why is he doing this...?? and then today he hasnt text or called me...