Why is my brother constantly annoying me?

I'm 15 an he's 12, he feels constantly compelled to annoy the s**t out of me. He gets in my way while waching tv, make these f***ing annoying noises and if i say anithing about it our parents take his side, buy him something he wants, and then he he throse a fit which is more annoying. He has nothing to do so ignoring him doesnt work, pluss he's a p***y so hitting him makes him throw a fit. I need some help shutting him up before i go crazy!