Watching Sis

I think I started masturbating, or at least trying to, when I was around 13
or so. I know that by the time I was in my mid 14s I was doing it pretty
regularly. I remember, because that summer my parents were having work done
on the house and I had to share a bedroom with my sister. Her bed was
nearest the window and as it was a large house set in the country with no
near neighbours, we would often sleep with the curtains and windows open.

I soon learned that moonlit nights allowed sufficient light for me to see
and I would often feign sleep to watch her masturbate. She'd often glance in
my direction to check I was asleep, but she never really caught me
looking... lol. She'd bend and part her knees, making a tent over herself
while she did it. Sometimes the duvet would fall off her shoulders and I'd
be able to see her other hand playing with her nipples.

She made a good job of controlling herself during orgasm, but very
occasionally when they must have been intense, she really struggled to
remain quiet and not move around too much. I would control myself as best I
could and would wait until she'd fallen to sleep, which she usually did
pretty quickly after cumming. I'd then slip one hand under me and bring
myself off.

There was one notable occasion in this time too. She had started dating a
local boy and our parents would let her stay out later on Friday and
Saturday. This one night, a Saturday I think, she came to bed having
undressed in the bathroom as usual. I had come to know that these nights
she'd usually do it to herself and was lying on my side, facing her bed,
feigning sleep as normal and waiting for the fun to start.

True to form, after I had waited for several minutes I saw her bend and part
her knees under the duvet. I saw the movement of her right hand go down to
her. It wasn't the brightest of nights (unfortunately), but good enough to
see nonetheless. However, unusually for her, I immediately noted that her
movements seemed more urgent and faster than normal. She was certainly less
cautious, with her glances towards me for example being minimal. Also, she
didn't seem to be concerned that the duvet was moving and shaking as her
hand worked away under it.

I sensed that she must have been really horny and aroused. That made me feel
equally excited, so I was struggling to keep control and stay still. Also,
her other hand was busy on her nipples and the movement had pushed the duvet
down well below her breasts so I could see what she was doing. Her short
nightie was fairly low cut and loose fitting so it was easy for her to get
her hand to her breasts. She looked as if she was really squeezing and
tugging at her right nipple with her left hand. She seemed to raise her head
as if straining to get it as far off the pillow as possible and then I heard
her gasping for breath.

I could vaguely see her mouth, which seemed to be wide open with her eyes
screwed tight shut. As she came she slammed her knees together and the duvet
started slipping to one side. As her orgasm finished I thought she'd settle
down and go to sleep as usual, but oh no, I was in for a surprise. Instead,
I saw her kick out with her left leg, presumably to try and re-straighten
the duvet, but this didn't work. Instead she lowered both her legs flat onto
the bed and then amazed me, as I saw that the duvet was still moving.

She was still playing with herself and her left hand was still busy on her
nipple. I couldn't resist letting one hand slowly slip down to myself, as I
realised she was going to try and cum again and without stopping from the
first time. I could hear the duvet rustling slightly over her hand movements
and I guess she realised that too, as she first glanced at me to check that
I was still asleep, before kicking it to one side with her foot. Suddenly I
could see her hand working at herself. Not clearly in real detail, but
enough. Her short nightie had been lifted nearly to her waist and I could
see her pubic hair, with her wrist resting on the lower part of her stomach,
as her fingers bent and arched while working at herself.

Her movements weren't really rapid, more rhythmic, but it was obvious when
she started to get close, as I saw her hips start to move and her pelvis
seem to thrust upwards. Her breathing also become very audible, taking on a
sort of gasping form. As she came I faintly heard her saying something, but
couldn't make out what, as the noise of my heart pounding in my chest seemed
to deafen everything. Shamefully that summer, my sister's sexual activities
formed a major part of my motivation to masturbate!