Erect in Front of Sis

As a naturist family we found nothing unusual in being naked all the time. Around the time I was about 13 I think I began to feel self conscious about myself as I was terrified I would get an erection in front of my mom or my sister who would have been around 15 at the time. I had never seen dad hard so knew he must be able to control it but I would often feel myself beginning to stiffen, especially if my sister was around.

One day the two of us were alone in the house and naked watching tv while mom was out in the garden and dad was at work. My sister had quite large breasts for her age and I kept sneaking looks at them when I felt my cock twitch and I knew I was about to get a hard-on. I grabbed a cushion but this gave the game away and Charlotte must have guessed so grabbed the cushion off me......

'I know you've been looking at my tits, Nat. Are they turning you on?'

I blushed and wished the earth would swallow me up as I looked down at my fully erect penis. She came and stood in front of me, legs slightly apart and I looked up to see her beautiful pussy was right in my eye-line.

She grabbed my hand and pulled me up out of the chair, pushing me out of the room 'Get to your room now or I'll tell mom'. I hurried upstairs, my erection swaying from side to side and dying of embarassment.

I lay on my bed hoping my cock would soften but I kept thinking of Charlotte's tits and pussy....I closed my eyes and started touching myself.....it felt so nice.

'Enjoying that?' I looked up and saw Charlotte in the doorway. Before I could say anything she came in my room and closed the door behind her. 'Keep doing it, I want to watch' she said as she came and stood next to my bed. I was so horny I did exactly as she had ordered, stroking myself while looking up at her beautiful body.

'Can I errrmmmm touch you' I felt myself mumbling, With that she reached down and took my hand off my cock, and moved it to between her legs, where I could feel her warm wet opening. She whimpered as I ran my finger along her slit before slipping my middle finger inside her. She grabbed my cock and started pumping it as I fingered her.

In a few seconds I fely my balls tighten, and I started shooting what felt like endless streams of jizz all over my tummy and chest. Her thighs clamped tight onto my hand 'Don't stop' she moaned, then she shuddered and let out a series of moans and whimpers, before removing my hand.

She smiled at me and kissed me full on the lips, tracing her tongue over my mouth 'I've been wathcing mom and dads porn collection' she laughed 'Theres so much more we can try, as long as we keep it a secret.....'