Against the rules (ereri fanfic)

16 year old Levi grew up with an abusive father and a drunk mother. When he was 12 he was put in the foster system with the philosophy "hurt others before they hurt you". 15 year old Eren grew up in a simple nice home until his father goes missing and his mother dies in a car accident . With no place to go he soon winds up in the foster system as well. After being bounced around for years, never finding a permanent home, both the boys end up in the same foster home. They soon find chemistry ignite between them but not only is their relationship frowned upon, it's against the rules for foster siblings to date. They soon find themselves in a battle between love, and obedience. But will rules define their love? Or will their chemistry conquer it all?