Living with your best friends boyfriend.....yeah that's awkward :/

So about two weeks ago we (my family and I) found out a friend of mine and boyfriend to my best friend was about to be made homeless due to circumstance that were out of his control. He has learning problem and is kinda immature but its not serious and not obvious unless you know you cant tell. So my parents asked him to move in with us and so he has.

I know it was never going to be easy but I have to say he is the most annoying, aggravating person I have ever met and that includes my sister which is saying something as most siblings argue and we are no different but this.....this is something else as he is constantly on and on and on. I walk in from school to find he sat there on my laptop without asking and then when I need it to type and research things for an essay he took twenty minute to actually log of the laptop because he want to talk to one of his friends! I've had to give him some of my bedroom furniture because he had none.

Then when he and my friend hang out on Saturdays they come back here and sit next to me which seeing as its his home for the time being he is entitled to do...but I feel awkward in my own home. I felt like a third wheel on their sorta date in my home. I don't see why I should feel the need to leave my living room just because he wants to bring my best friend home and even she has said that she feels awkward coming here to hang out with her boyfriend with me being here.

He treats me and my sister like he's the boss and orders us around like its his god given right to do so and it really bugging me now. I know I sound like a spoilt brat because he's moved in and what not but I just cant stand him and he doesn't wash so he smells really bad :(

Oh and did I mention that he has started calling my mum, 'mum' SHE'S NOT YOUR MUM!!! She's mine! I cant do anything without he being there. And if I snap at him my parents take his side over me and my sister! Its just not fair.