Friend trouble please help?

Okay so I go to the weightroom everyday and this kid who started coming I've know him from school whose a smaller guy but thinks he's a hardass and good at sPorts when he's not and that he drIves well he came and I was doing my first set of military press 50 lbs I'm 15 and he's talking to be bragging and I'm like mhmm yea okay mhmm well let's see if you can do this then he did it like he was all bad *** and I'm like you know I always start off like you know I always star off easy on my first set right then a kid that I've known since fourth grade and we've always been really close came and worked out with that other kid and was just being kind of a dick to me like making smart comments and making me look retarded I lift more then he does I'm in the the top 15 in my school in weight lifting well today I wanted to seriously kick his *** why was he doing this?