A secret brother and sisters secret romance

My name is Sean and I grew up in a large family; three sisters and two brothers. I was the fifth born out of the six. My two older sisters and two older brothers are within a year apart and at least ten years older than me. When I was two my little sister Mary was born. Mary was like a gift from god for me. With both of my parents working and my brothers and sisters living their lives Mary and I became more like companions than brother and sister.
Mary and I grew to depend on one another. I looked out for her and she looked out for me. It wasn’t long after Mary’s birthday when our father died of a heart attack. Mary and I became even closer when the rest of the family became more withdrawn from each other. Our mother tried to keep us strong and together but all of our older brothers and sisters moved out and started their own lives. They keep in touch and we still talk just over the phone.
Our mom received a healthy life insurance claim from our father so she didn’t have to work anymore. This caused her to become even more disconnected with reality. She started to drink heavily she would smoke almost two packs of cigarettes a day. Mary and I were forced to take care of each other until I turned nineteen in 1993. That’s when I came home from work and found my mother lying face down on the bathroom floor. She was there all day and I couldn’t let Mary see her. I contacted her school and asked if they could keep her there until I came to get her and not to let her know why. It took about two and a half hours for the police and coroner to do their thing and get out of the house so I could go and get Mary and bring her home.