We were watching TV on a Saturday night. It was summer but the weather was awful. The rain was pounding against the house. My sister asked me
'If I take off my top will you take off your bottoms?'
Now we were not talking about sex or anything. We had never done anything not even show me yours and I will show you mine. So the question was a complete susprise. I had a small patch of pubic hair and a growing cock, five inches hard. So I was not ashamed of my equipment. I had no experience at all with sex except my own hand. I certainly wanted to get some. My sister was fifteen about average in everything. I would have loved to see her tits. So after a moment I thought I told her sure. My dick was aching already.
But nothing from her. I asked her if she was going to do it. She said no. Sick of it, I went to my bedroom to jerk off. I shut the door and got started. I was still rubbing it slow when I saw the door was opening. It was just open a little but I knew my sister was out there watching. I never had an audience and found the idea thrilling. I made it last as long as possible. Finally I shot several globs high into the air.
I started appearing naked in front of her. She never complained. I would try to stay in her room when she was changing or in the bathroom before her bath. Sometimes she let me stay. I would massage her back and legs. She usually stopped me when I tried to rub her tits or ass. But not always.
I played with her pussy and fingered her during some of these massages. I jerked off in front of her hundreds of times. She jerked me off many times. I humped her ass over her clothes with her on her back several times. We were engaged several times a week in some form of sexual act till she started college. Then it stopped for several years.
But I still grab a feel from her when we are alone. If she come over to my house when no one else is there, we do it.