s****r is a slag

i was 16 when i first noticed my s****r properly she had just turned 18 and wow, i walked past her room one day and she left the door open just enough for me to see into her room, i pressed myself against the door frame and looked in to see my beautiful s****r getting changed into a skimpy little night dress as i watched i felt my cock get harder and harder just watching her thong fall to the floor and as she bent over to pick up her hairbrush all i could see was this amazing mound of an arse, i ran to my room to jack off and came instantly. 2 days passed since i peered into my s****rs room that night and i was feeling brave. i waited in my room silent untill i knew she would be sound asl**p, i longed to see her tits and to touch her body, i saw that it was after 2 in the morning and thought this was my time to go. i crept silently down the hall to her room my breathing got heavier as i saw the door open and the light on my head span as i looked into the tiny room. i saw her laying there passed out on the bed with nothing but a thong and a strap top on, my cock got so hard looking at her so i walked slowly into her room trying to control my breathing. i slowly pulled up the top of her top to see her beautiful DD boobs her nipples were hard so i pulled her top down and let her boobs flop out. she started to breath harder so i backed off waiting to see if she would wake her eyes opened slightly so i bolted out the door back to my room and jercked my hard cock till i came. the next morning she walked downstairs to find me sat at the dining table in my dressing gown she sat opposite me in a pair or short shorts and the same top she had on that night and asked where our parents were, they had gone away for a few nights probably on a dirty weekend as i said this her eyes lit up with joy, i was confused i thought this may meen she would have mates over that night but when i asked why she was so happy all of a sudden her face whent bright red as she dissapeared from the table. i went about my daily business and got the things i had to do done, i realised i had not seen my s****r all day so i ventured upstairs to see what she was doing if anything i was going up there to see if she was getting naked for some reason, but all i found when i got to her room was her asl**p on the bed still in her shorts and top, i walked over to her and shook her a bit to see if she was really deep in sl**p and nothing not even a grunt, so i took this chance to really see her body. the top she had on that day was really short so i could see her perfectly tonned body, her legs were long and slender and wide open on the bed, her shorts being so short i could see her panties from the side of the shorts so i decided to put one finger under her shorts and move them further to one side. with this i could see her thong and the tiny little wet patch that was near her pussy which was outlined perfectly by this thong that was probably too small for her but she didnt care. i stood there and pulled my cock out my boxers and started to rub my cock over her body i was not watching her face but all i heard was heavy breathing and then she moved.................. if you want some more comment and let me know and i will write the rest of the story out x