I had always fantasised aboout my girlfriends younger sister (Amber who was 17) she was slim, size 8, pert breasts and gorgeous little ass.
Anyway, my girlfriend had an Ann Summers party one night at her house(she still lived with her mum and sister at this point) and I went out with my mates, when I returned home to there house it was my girlfriend and Amber that were still in the house, I asked how the party had gone and she said it was great, she said Amber finally got a rampant rabbit vibrator, I turned to Amber and she got very embarrassed and went bright red.
A few weeks later I was staying the night at hers it was a Sunday and my girlfriend and her mum both had work the next day, I was off as I worked shifts. Anyway, I awoke the next morning my girlfriend had already left and I was as usual feeling very horny, I could hear the hairdryer coming from her sisters room, I decided to get up to go to the toilet and see if I could get a perv at her sister while passing her bedroom. I was in luck as I walked past she was stood in front of the mirror drying her hair. She was wearing a tiny little silk night dress that barely covered her hot little ass, I stood here for a minute in my boxers with my semi hard cock and had a good look at her before popping my head in and saying good morning to her, she turned and said good morning back and I nipped off to the toilet.
When I returned I looked in again, she had finished doing her hair and was getting dressed. She was stood there in her bra and panties, I stopped and looked, as I did she turned round and looked at me, I popped my head in again and told her I was just going back to bed for an hour. When I got back into bed I was super horny and started to wank off, I had left the bedroom door open a little so I could see her if she came out of the room. A few minutes had passed and it got very quiet, I stopped wanking for a second and I could hear a buzzing noise coming from her room, as soon as I heard it I knew that it was her new vibrator.
I got out of bed naked with my throbbing hard cock bobbing around as I walked through to the hallway to have a look in her room. The door was hardly open at all and could not see her bed directly but I could see her in the mirror lying in bed with her head right back, I could not see her bottom half but it was obvious that she was fucking herself with her new toy. I was so turned on by this point I couldn't stop wanking, I went back into the toilet and got a pair of her panties that were in the laundry basket(I had wanked off in her dirty panties so many times before) I went back out to the hall and stood there wanking my cock into her panties, within seconds I came all over them, she then let out a loud moan and switched off the vibrator. I got back into my room, still with her panties wrapped around my cock and got back into bed, about 10 mins later she tapped on the door and said that was her away to work now.
When I heard the front door close I went straight into her room looking for the vibrator, I found it in her knicker drawer, first thing I did was put it in my mouth, the taste of her pussy was so good, I grabbed my cock again and shot my load all over her bed covers. It was so horny, I couldn't believe it had happend.