Why is my cousin so mean to me?

Okay so my cousin is like 17 or 18... i dunno lol and I'm 11... he stays by us sometimes when he has nothing to do according to him and stays for really lol and hes fun sumtimes but a lot of times he just says mean stuff to me like saying im a les (I AM NOOTTTTT) and saying how I'm a, and I quote 'hot mess', calling my a and other crap and personally although i never told him to his face he acts gay and girlish saying how hes fabulous and listening to lady gaga (hes a huge fan) and saying how the music i listen to is crap and how i dont know real rock cause i listen to like linkin park and stuff (and aerosmith and the beatles) and he listens to glam rock and says how david bowie is a legend.. and he would compliment me and then say "just kidding ******" and he would suck up and say stuff like "hey will you go get me some water please ill be your favorite cousin" and i would say "go get it yourself" cause whenever i do it he just says "thank you bitcchh and youre not my favorite cousin" and his dream is to go to new york and be a male model (WTFFF???) and I just wnana know why hes so mean and he keeps calling himself fabulous and amazing and I'm a pretty nice person so im not mean to him I just say "okay cool.." but I'm sick of him acting like such an a**hole... forgive my language lol... why is he so mean to me and what should I do about it?