Jack off Sister

When I was 15 and my sister was 17 she had a door to her bedroom and it didn't have a doorknob, and just about every night I would go and look through to see her getting undressed for bed. On weekend nights because we stayed up later when she was done, and in bed I would go in and ask if she wanted to play a board game? Most of the time she would say yes and I would sit on the floor and she would lay on the bed.(I made sure the board was far enough away that she would have to lean over and I could look down her nightie and see her tits)

As we played and me looking at her tits I would get hard and one night my dick popped out of my underwear and she said 'Do you need a hand with that?' and not waiting for an answer she reached over and started to jack me off. After about five minutes I shot a large load all over my shirt and leg. After that night we would get together once or twice a week until she went to college. When we can't find time to get together now I still think back and do myself.