I need some advice. Until a month ago I had never thought of my sister sexually. I knew she was attractive, most of my friends have been talking about nailing her for years. I slept in on Saturday and didn't wake up until 3 in the afternoon. So at first I thought I was home alone, until I heard music coming from my sisters room when I walked past to take a leak. I was planing on ordering a pizza so I knocked on my sisters door and walked into her room. So there she is, butt ass naked, some boy I'd never seen balls deep in her. She was doing a reverse cow girl so I got a full on look at her, she was so into it that she didn't notice me right away. I just stood there speechless for a few seconds, our eyes met and I simply left closing the door behind me. I was sitting in my room the image of my sisters naked body burned into my brain, when she burst in about the same time I heard someone running down stairs and out the door. First she yelled at me for coming into her room, then yelling at me for even being home, I was suppose to be at work all day, finally she ended in tears begging me not to tell our mom and dad. She said she would do anything if I promised not to tell them, and by the look on her face I believe she meant anything. I told her I wouldn't tell them until I thought about it.
I haven't been able to stop thinking about her. Last night I had a dream about her and woke up with a massive hard on. I'm almost certain if I say I going to tell on her unless she sleeps with me, she'll go for it.
So should I?
