Thank you everyone for helping me with my decision. I will definitely be telling my dad about this situation. This is an update about the poll I made yesterday.

1. My dad works to pay for groceries and the bills so he cannot be home with us all the time.

2. I know many of you said that my sister must have been raped/molested for her to have the mindset that she does. I know many of you will argue with me and say that I would not know if my sister has been sexually abused or not. My sister has NOT been raped or molested in her life. We are literally those type of twins that do every single thing together. Our class schedules have been the same for years. My dad is a good father and we have never been left alone with ANYONE before besides when we could have our close friends over. He's very protective of us. We have never even been left alone with his best friend before. Every time his best friend was over, my dad was always with him.

3. The age of consent is 16. We do not have "Age of consent gap provisions" that would make this illegal. It's legal and my dad's best friend cannot go to jail for this.

4. My sister has that weird type fetish for older guys and I knew about that. She has never done anything sexual with an older guy because it would be illegal if we were 15. She knew that both parties could get in trouble so she waited for when she could consent legally with older guys. She always joked around with me that she will find a sugar daddy one day to take care of her and buy her expensive things. She doesn't want to end up like my dad making ends meet and having to make a money budget. Our dad tries his best to get us at least one special gift during our birthday and holidays. She wants expensive and special gifts all the time.

5. She's had sex with guys our own age and she doesn't like it because they aren't experienced enough and teen guys don't know what a woman likes in bed. (Yes, we talk about sex).

6. Our mother was the same way as my sister. My mother had an affair and ran off with the guy she cheated on my dad with. This was 10 years ago and my dad, sister, and myself have all been going to family therapy and individual therapy for nine years. We all still go to therapy. I'm guessing her actions have something to do with my mother's past actions.

Thank you everyone for your advice and help. I will keep you updated when I have the conversation with my dad. Also, I will make sure that there are no weapons around.