How do I deal with my mums boyfriend that I hate?

ever since my mum has been seeing him everything in my house has changed like the second time he came to my house he already started laying rules on how I should live and what I can and can't do, now they have been seeing each other for over 6 months and I just cant stand to be around him, he doesn't consider other peoples thought it just always has to be how he likes it and when ever my mum and him have a fight he goes and buys some fancy electronical thing lik a tv or something expensive just so my mum will feel to guilty to leave him after he brought her that, and if i talk about something I want lik a pet he says "your not bringing that here take it to your dads" and I just feel lik yelling at him and saying who do u think you are you don't own me or this house so why should everything always be up to you but of course I can't say that to him, and he crys lik every second day but he puts on this big tuff guy act and goes to the gym, I tell my mum to realize what he is truely lik but she's to gullible to his manipulation and says that I encourage him to go against me and she always defends him with what ever the situation is, and she won't admit that we live by his rules I think she denies it because she knows it's true but dosent know why we continue to follow them, I'm 16 I live with my mum and i don't know how else to deal with him without suffering in silence.