Why does my dance teacher treat me like a utter child it pees me of so much i cant change dance cl either?

ok so first of this is not a school dance cl and cant change dance cles as this is the only one in my area and the instructor is my brother best friend and has known me since i was 5 but he still treats me like im a actual five year older today i wore leggings instead of sweats and most other girls wear leggings and he says nothing to them but today he was like nd why are you wearing them young lady your not going to be able to dance properly its not a fashion show' and that peed me off also he was annoying me when other girls where dancing giving me a lecture about saying how i drink far to much for my age and i accidentally said **** of and he made me go stand in 'the corner' for 5 mints then came over With his stupid Accent like ready to say sorry and made me hug him and tied my hair up for me cause it was in my face which also peed me off because i look like a boy when its tied up cause its to short :'( then at the break time i was showing my friend my phone i got for christmas and he came over talking in a baby gooey voice going ooh isn't this a Pretty phone wow Touch screen you know how to use it all Very patronising ? what the hell am i doing for this to happen to me