For a year now, I've been renting a spare room at my aunt's house. She has 3 children, and the oldest one moved out a few years ago, and it's his room I'm renting. I'm 19 years old, and my two cousins still living there are 17 (girl) and 19 (boy).
I have no problems with the girl, she's in fact my best friend and we became even closer when I moved in. She's the top reason why I'm still living there. My problem is mainly with the boy, and some with my aunt.
Because we're all family, food is included in my rent, I eat with them and I share bathroom, living room and all other areas of the house with them. The boy however, doesn't seem to understand that while all the food his mother buys is just as much mine as it is his; food or snacks I buy for my own money is mine, and something I buy because I want to keep my aunt's expenses to a minimum, not because I'm dying to share it with him.
If I'm away for a weekend to visit my parents, he will go through my room and search my desk for snacks. And if he's out of cigarettes, he will take mine, even though there's a convenience store right across the street. It's practically just as close to the store as it is to my room.
In short, he's a brat. In his mind, he has first claim to the tv/stereo/living room/dvd player/nintendo wii/nintendo gamecube/nintendo 64, and even to the flat screen in his sister's bedroom.
He doesn't go to school and is basically just living off his mum while he's claiming to be ill with some disease no one has ever heard of, and no doctors can find. Therefore he does not have to get up at 6:30am unlike me, his sister and his mother, and when I get back from school, he's usually in bed. AT 4PM! This does not bother me at all, what does bother me is that he finds it perfectly appropriate to play piano in the middle of the night, keeping us and the next door neighbor's baby awake. I will wake up at 3am to the sound of the theme-song from McGyver, something I would find hilarious if I didn't have to get up in 3 and a half hours.
The only problem I have with my aunt is basically that she does nothing to make her son behave, and keeps making excuses for him. Also, if there's something in the house she's not happy with, that relates to my being there, she will tell my parents. Not me, my parents. Clearly she sees both of the 19 year olds in the house as children, even though only one of them behaves as such.