Why is my brother such a self-fish sob?

My brother is 18 years old and still ask my parents for money. All he does is just go out all night. Sometimes he don't even come home. And whenever you see him at home. He is usually asking my parents for more money. And my parents give it to him. What kind of behaviour is this...? My parents just keep on spoiling him and always needs to "invite" him to come it dinner with us. (Have to phone him everyday!) I see this and it just pisses me off. I have to work for everything I get. And he is just having a free ride out of life Never having to learn that you have to earn your money.Plus he is a slob...!! (doesn't clean up after himself!)