This happened around the beginning of December.
I have been masturbating for almost a year and and do it once sometimes twice a day. When ever I am home alone I go to my computer to look at the archive on this website for stories that turn me on. My favorite are the ones including siblings or father/son/daughter or mother/son/daughter.
Well anyways my mom was room-mom for my class and the Christmas party was coming up that week so my mom had asked me to asseble goody bags as she and my sister were going to run some earands. I always like the idea of combining everyday things with being nude so I decided I would put the bags together nude sitting on the capet floor in the room near the fronr door. I thought this way I would hear or see someone long before they come to the door. I like to play a sort of game where I see how long I can stay with out getting hard wich usually doesn't last long. After what I thought was only about 10 minutes I looked up and saw two figures moving toward our door. I stood up and started to grab for my cloths but it was to late. My mom walked into the door in a mid-conversation with my sister and looked over at me and gasped. My sister (14) just giggled. I thought I was going to die. I couldn't move I just sat there waiting for something to happen. My mom said that it was OK but just go upstairs. I quickly grabbed my cloths and ran upstairs to the bathroom. When I got up there I noticed that my dick was rock hard.
My mom works early on saturdays so when I woke up she was gone and my dad had been out on a buisness trip. I went downstairs to watch T.V. when I heard my sister coming up the stairs. She came over to me and asked if she could see me jack off. I was shocked and said no. She said that yesteday made her really horny and when she went to sleep she sat there thinking of me. This started to get me turned on and I think she noticed the growing buldge in my pants. I said I would get naked if she would. She instanly agreed and in no time she and I had stripped. I had never seen another girl naked before expept in magazines and she looked amazing. Her tits were small but beautiful and her pussy was neatly shaved and wet. She walked over to me and to my suprise took my meat in one had and shover her other hand in her pussy. She jacked me and it felt amazing. After only a few minutes of her pounding my meat I came all over her. She rubed my cum over her tits. I did somethig bold and put two fingers in her pussy. That was enough, she came. After we cleaned up she thanked me and I thanked her.
My sister and I have masturbated tggether once more in the past week and it has been great.