Until the age of 15 I used to share a room with my twin sister. We used to stay in a small two bedroom apartment with my parents and there was just not enough room to get us each a separate room. I never really cared about it and neither did my sister as we just grew up that way. Every evening we used to talk about all different kind of things but somehow we never talked about anything regarding masturbation or sex. We've even never seen each other naked since we were small children as we used to change always in the bathroom. The most I've ever got to see was my sister in her underwear and I can't remember if she has ever seen me naked.
My parents used to work both long hours so every day after school we spent the rest of the day alone at home if none of us was out with friends or doing sports. Usually we were watching TV or just played games.
One day, we were watching TV as usual, my sister came up with a question that really surprised me. Out of the blue she asked me if would like to get naked! I was really terrified by that question and asked her why she would like me to get naked? She just said that she had never seen a boy naked and that she would like to see my penis. At first I said no, but then she offered me that I could also see a part of her body if I would like to. I started to think as I've never seen a girl naked at that time and eventually I said yes, but I also insisted that she has to show me something first. She agreed and she took of her t-shirt straight away. Then she undid her bra and stood right in front of me showing her perfectly shaped breasts. Then she moved closer to me until her breasts were just a couple of inches away from my face.
By that time I was rock hard and I wasn't able to say anything. I wanted to ask her if I could touch them but I just couldn't as my voice was just gone. She stood there for a couple of seconds and just as if she could read my mind she asked me if I would like to touch them. I just nodded my head and started to feel her soft skin and her nipples. It felt amazing.
This went on for about a minute as she reminded me that we agreed that I would get naked if she would show me something. I quickly took off my clothes and there I was, standing completely nude in front of my sister with my small erect penis. She looked at it and without asking she started to feel my balls and pull my foreskin forth and back slowly. It felt so good to be touched by somebody else that I just let her do without saying anything. This went on for almost a minute as she stopped and asked me if I would masturbate from time to time. I told her that I would. She looked at me for a couple of seconds and asked me if I would like to sit on her chest while she would lay down on the floor and continue playing with my penis.
I quickly agreed and the next moment she was lying on the floor while I took place on her chest, her boobs between my legs and her face right in front of me. She grabbed my penis and continued what she had started before. It took only one more minute before I felt the nice feeling and I told her that I was about to cum. I expected her to move away but instead she just lifted her head and opened her mouth. The next thing I shot four or five ropes of cum of which three went straight into her mouth. The rest landed on her chin and her shoulder. We stayed in this position for about two minutes without saying anything. Then she told me that we should get dressed before our parents would come home, which we did.
After that we talked about what happened and she explained me that the girls in her class were talking about handjobs and how nice cum would taste and that she just wanted to taste it to be able to know what they were talking about. She told me that she really liked the taste of it and that we could do this more often if I would like to. I totally agreed but also mentioned that next time I would like to see more than just her boobs.
The next day we continued what we agreed on but this is a story for the next time