It started out as a normal day. I picked up my little sister from school and we came home to an empty home again, our parents were always busy with work. I try my hardest to take care of her, cook her food, and help with homework. As a result we’re pretty close, sometimes I think she sees me as more of her mom than our actual mom is. When she’s had a nightmare she comes to my room, when she’s bored she’ll see what I’m doing, we watch movies together and play games. Sometimes it feels like we’re glued at the hip, but I don't mind.

	Our parents had asked me to pick some stuff up from the store, so after we got home from school I set her up on my computer to play some games before heading out. I didn’t give much thought to it, it's something I’ve done before and she’s a smart girl so I didn’t expect her to download any computer viruses or anything. I forgot what I did last night, what was still open in my browser tabs. 

	I got home and carried the bags in, “Alice!” I called. No reply. A bit strange, she usually comes to the door to help put stuff away. I head to my room to check on her. When I open the door it feels like a piano fell on me. There she was, staring intently at the screen, reading the porn I had left open last night. I could see it, the older sister character was taking the younger from behind, they were screaming how much they loved each other. Next panel the older would flip the younger around and the younger would say to cum inside. I swallowed the knot that had formed in my throat and closed the door behind me.

	“H-hey lil sis… uh whatcha lookin at?” I had no outs and I knew it. She was gonna tell our parents and I’d be kicked out, maybe even branded a pedophile. Tears wanted to come but I held them back and took a deep breath.

	Alice stared up at me, I was so nervous I was sweating. I had no idea what to do with my hands. I kept muttering half formed excuses and explanations. She stood and took a step towards me, I took a step back, she took another step forward, and I back again. We continue like this till I hit my bed and fall back onto it. She climbs on top of me… she’s... warm… And then it dawns on me, that wasn’t the tab I left off on last night. I look at her again and I notice her face, flush, her breathing heavy. Oh no. Oh no. Oh no no no nononononono.

	“Uh… sis? How many of those did you read? You know uh that stuff is… I mean it’s not uh… We can’t…” The words I need to say won't come out. My arms, strong enough to carry her easily, would not move. I was frozen in fear, sweating profusely, breathing heavily. She was at my waist now.

	Finally Alice responded, “You like this right sis? I saw all those comics you had open, all about sisters.” She places a hand on one of my breasts and I tremble. “There were so many, it must be normal for sisters to do those things right? They look so happy. I want to make you happy too sis.”

	God help me. Every fiber of my being is screaming to act, but there was a war in my mind over what act that would be. It should have been easy. I had thought about this before. Many times. When she was sitting in my lap while we watched movies, when she would crawl into bed and cuddle me,  when she would fall asleep on my chest, every little intimate moment had been a temptation that I had overcome. Why now was it so hard. Why.

	“W-w-w… we can’t…” I say, but only a whisper comes out. My hands had been hovering close to her, shaking. Finally I give up, I can’t bring myself to push her off. Instead I wrap my arms around her and pull her closer. God she's so warm. My heart thunders away in my chest, I’m sure she can hear it. Pulling her closer puts her head right between my breasts, and her waist right on top of mine. I feel her hardon for the first time against me as mine presses against her. It feels like we lay there like that for an eternity. 

	All is still, I realize I can feel her heart pounding too. I hear myself say,  “Promise me you wont tell anyone.”  I feel her head nod on my chest. It’s ok right? She wants this too. I can feel her being just as turned on as I am. It can be ok… if it's her… I lift her up so she’s sitting upright on my lap. “Nobody can know… This is only for sisters, ok?” She nods again. 

	“Do you know what to do?” She shook her head no.

	“Ok.” My body moved as if on its own, my hands under her shirt and up, removing it. Down to her skirt, removing that. Her little girl dick twitched every time I touched her in a new place. I place my hands on her face and kiss, forcing my tongue into her mouth to lap against hers. Nibbling her lip, encouraging her to do the same. When we part a line of drool drips down onto her chest and her tongue hangs out while she pants. Her girl parts have leaked all over my shirt and pants, so I go to take them off. The shirt, the pants, and my bra and underwear. 

	I pause briefly, wondering if this is a dream or if I’m really doing this. I ask, “Would you like to do what those sisters were doing? Me inside you?” She does what I think was a nod, and I flip her over to face down on my bed. I take a bottle of lube and begin to rub the rim of her asshole with it. She whimpers slightly at the coolness of it against her hot body. I press my finger in, applying more lube generously and putting some on my girlcock. I pick her up again to bring her butt to my waist, it’s so easy she feels like a feather, and I press in.

	Slowly. I ask “Does it hurt? If it does, tell me.” She just whimpers. “You’re doing good sis, just a little bit further…” My breathing turns heavy again. I’m inside her…  I’m inside my little sister! Oh god I’m inside her. I try to thrust for the first time but something catches in my throat, a sob. I pull out and sit there, staring at the naked sister with a slightly gaping anus before me. “What am I doing. What have I done.” I start crying, sobbing, but Alice turns to me and wipes my tears away.

	“It’s ok big sis, I want this too. I want to be close with you… I want to share everything with you.” She leans back and puts her legs up, spreading her cheeks with her hands. “I saw this in one of the comics, am I doing it right?”

	The sobs turn into a chuckle and I smile. “Yeah. You’re doing it right.” I push her legs up further and push myself back inside her. I look down at her and she smiles at me. I start thrusting and she arcs her head back. Faster, she starts moaning. Faster, she starts making little arfs. Faster, she’s howling now. Howling, moaning and barking. She’s happy. I see that now. She was right. She straddles me with her legs and I smile now, grabbing her waist and thrusting harder, teasing her nipples with my fingers which in turn makes her louder.

	I cum inside her and scream “Lil sis!” She cums too and yells back “Big sis!” We both pant in silence for a while, holding that position, basking in the moment. 

	Later, at dinner, Dad would ask, “Anything interesting happen today?” and we’d smile at eachother. “Nothing unusual no.”  After all it’s normal for sisters.