Cyrain was your step brother, he was the golden child and your parents didn't even hide it. You two would argue and hit eachother Cyrain would always steal your stuff and wouldn't give it back until you did something for him. He ended up taking your money and when you found out you immediately went to his room you asked for your money, it was a total of 2k that you've been saving up.

"Hmm, then let me get half of your money." you said no and then he got upset and ran to your parents to make you let him keep ur money.