Not 18 but was my only option.

4 the first time in my life I am shaken. sisters BF and she have sex all the time. She tells me all about it. How big he is and good it feels. Well I just can not tell her what I just found in our garage. Mom in the car and sisters BF having sex with her. Mom was moaning and yelled when he screamed. Said he did it to quick. She then sucked his penis. She did this and made him get on top of her again. She moaned again and again. He moaned and she got mad, I know what her mad look is. She got dressed and told him next time be a man. I don't know what that means.

I am worried my dad will find out and make him stop visiting the house. He is taking me with my sister to a concert next weekend. WTF