Inside my sister for the first time

I had just watched her have sex with my uncle - and had a thought

My uncle was always molesting my sister after she turned 18 - and not me so much, anymore - i took to watching the two of them as he sexed her in all different positions - i really liked the ones where i could see his cock in her pussy.

Sometimes I'd get hard just from seeing it move back and forth making her moan and sigh like that. Then one day, after he was done with her, my uncle left me alone in there with her for a little while before taking us both home.

I had always wondered what sex would feel like, so when she lay there, still breathing hard from the exertion of getting off on the old perv, i decided to find out.

She opened one eye and looked at me. "What do you think you're doing?" she asked. her voice sounded funny and far away. it didn't really sound like her.

"I want to see what it feels like," i said simply.

Her other eye slid open then, looking at me with a strange mixture of fear and curiosity. "are you sure?" she whispered.

"yeah."

She nodded once, slowly. "okay," she said, her voice barely audible above the sound of our breathing. "but don't tell mom or dad. Okay?"

I nodded back. my cock was already hard and leaking pre-cum just from imagining what it would feel like to slide into her wet pussy. she reached out, her hand shaking a little as she wrapped her fingers around me, guiding me towards her.

It felt so good when I finally slid inside of her. tighter than I thought it would be, but not painful or anything. Her skin was warm and smooth and wet. i started moving in and out of her slowly at first, feeling the head of my cock brushing against something inside of her that made her moan.

She reached up and put her hand over my mouth. "shush," she hissed. "we don't want uncle to hear us." but it was too late; she had already started bucking her hips, meeting my thrusts with a desperate urgency. it felt so good for both of us that I couldn't help but let out a soft moan before quickly pressing my hand back over her mouth to muffle the sound. She came again, hard this time, her body arching off the bed as her nails dug painfully into my shoulders and her legs trembled beneath me. It was almost more than i could take; the feel of her pussy squeezing my cock as she orgasmed made me lose control, coming inside of her with a harsh groan that thankfully didn't seem to carry far enough for uncle to hear.

When we were both spent and gasping for air, i helped her lie back down on the bed. "thanks," she whispered, her eyes closed. "that was... really nice."

I didn't say anything; there didn't seem to be any words that could describe what had just happened between us. instead, i leaned in and kissed her softly on the lips before rolling off of her and onto my side, leaving us both to fall asleep in each other's arms.