Brother in law

I don't know what section to put this in but I just need to vent. My brother in law is 13 and I really don't want to say this, but I can't stand him. I'm not going keep him out of our lives because is my SO's brother, obviously, but he literally makes me want to scream. He stays the night with us occasionally just to spend time with us and when he's here I literally want to run away from home. He's gross, annoying, whiney.... I could go on for days. He breathes so loud I can hear it from across the room with the tv turned up. He pee's on the toilet seat and doesn't wipe it off and doesn't flush the toilet so I walk in the bathroom and it smells like urine. He smells quite horribly considering he's overweening and doesn't shower often. He eats more than my family of four and myself combined and he makes a huge mess while doing so. Even if I fix him a plate, he will still go out of his way and take food off my plate. He whines 24/7 because all he wants to do is ride out $10,000 ATV and I won't let home because he will mess it up.... I just wanna scream!