My sis was 15
Well this happened like four years ago. My sister and I are very good friends. We live in a small house so we had to share a room and a bathroom. We were very comfortable about talking about or sexual things. We both knew the other one had masturbated.
So one night our parents left us alone and I was feeling pretty horny. SO I went to the bathroom to jackoff. Well while I was jacking-off my sister heard me moaning and went to see if I was alright. She opened the door that I forgot to lock and she lets out a small shriek. She does not leave though. Her face turns very red. I yelled at her to get out which she did.
After she walked out I was not able to cum so I went out. She told me 'wow you're a little horny kid aren't you.' I blushed she then said, 'well I am pretty horny too'.
I asked well then do you want me to help. she said she thought I would never ask. She pulled off her shorts I did too. She then grabbed my dick and started to tug. I came very fast. She told me to help her get off. So I stick my hands on her clit and started to finger her. She kept moaning harder...harder...faster then she orgasmed. we both sat there panting. After that we both showered together. We both orgasmed again in the shower.
This was a awsome night. We have done this a couple of other times since. well now after writing this I'm a pretty horny so bye