My stepson is rude and racist. He constantly refers to people of another colour as the taliban and everything that goes wrong is "gay". His dad doesn't do anything when he makes these comments and I am left seething with rage afterwards. He shouts "allah Akbar" all the time, constantly makes ridiculous noise and is allowed to play 18+ games. He also watches a number of shows completely inappropriate for his age such as game of thrones and rock and morty. I have tried to discuss this with my partner in a polite and calm way where I don't over step my boundaries but he gets defensive and doesn't listen. The child never says please or thank you and if you ask him anything he just says "what?" He gets very frustrated when he loses games and strops when he is told off. He bangs and clashes around my flat, insults me and calls my cat "skinny flea bag." I've told his father that I don't find this behaviour appropriate and I don't want him to do it any longer and he says nothing. The child also swears and curses all the time. He doesn't talk properly either and is really unclean. He won't take a shower when he stays and refuses to reuse cups for drinks making a hell of a lot of work.
He also throws things around when he's bored of them, pushes me out of the way when he wants to get past and is always getting involved with conversations that me and his dad have in a destructive way. He will gang up on me and his dad whenever there is a slight dispute.
He also constantly says that he doesn't like his mum. He has told me he has to sleep on the floor on a mattress at home and only gets fed chips and pizza. He tells me he gets his siblings ready for school every morning and his mum doesn't walk them to school (they are all under 11, him being the eldest)
I can't help resenting his visits as his dad lets him rule the house, eats all my diet food and moans about the fact he can't share a room with us. I've had the argument time and time again about him staying in my bedroom saying that it's unhealthy and not ok but it seems to fall on deaf ears.
He is allowed free reign on the computer and stays up all night on online games.
Help me, I'm tearing my hair out!!!