Needing to vent

I'm a teenager with a toddler and still live with my mom and stepdad. Anyways two years ago my stepbrother (who is in his 30's) moved in with us and brought his toddler son as well. He moved in because him and his at the time wife were going through a bad divorce and didn't have the money to get a place to live. He was only supposed to be here for six months, also everybody in the house had to move around and give up things for them (my 7 year old nephew lives with us and he had to move out of his own room and into my moms room so my stepbrother had somewhere to sleep with his son) Two years later and he's still here and honestly it's really starting to bother me. I know very well he has the money to move since he's been here he's bought several expensive things like new iPhones, flat screen tvs, and three brand new vehicles. Which is the part I care less about what I do care about is the way he is about stuff. Like all three of the kids are milk drinkers so we always have at most three jugs of milk in the fridge. One of them will already be opened but he'll go and open the one that's not open yet even though there's already a opened half jug of milk in there. We share a bathroom and he constantly leaves pee in the toilet with the seat up, has Monster energy drinks just sitting on the counter and the counter is constantly soaking wet from where he turned the sink on and didn't clean the water that splashed out. His son is 5 and is constantly mean to my 1 year old, and always trying to break my sons toys. Also he uses the washer almost everyday and literally washes like three pair of pants and four shirts at one time, that's it. We have 7 people in this house and we all have to use the washer too. I'm just irritated because it's over crowded in here and he was supposed to be moved out a long time ago.🤦🏻‍♀️ I just wish I could say everything that is going on but I'd be here typing all day. Sorry guys I just needed to vent, it's just really frustrating and I would gladly move out if I could but I'm not of age, nor do I have a car or job, and the way I see it is he's 30 and I'm only 17. He should be the one leaving. Oh and I feel like the reason why he won't leave is because he doesn't have to pay for anything here, no bills or anything, he doesn't even help buy groceries or do anything, I help out when I can.
**My mom has wanted him gone as well, my stepdad and her have both argued over it bad before, my stepdad will NOT kick him out.