Family Member But Not Related By Blood

Nick is like a brother or cousin to me. He became part of my family when he was a little bit younger then me. My mom took him in because him and his mom were having problems and he knew my mom and my sisters already and they told him he could come stay with us if he wants and he said yea. He lived with us for for about a year or two and ever since then he has been a brother or a cousin to me and been really close to my family.