My sister Riley (Huge Cock route)

"Hey sis! It's time to get up!," my sis Riley said as she opened the door. Riley is three years older than me, making her 22. If there is one thing I am jealous about, it is her body. She is 6ft tall, with mile long legs and, as mentioned before, D cup breasts. She is as smart as she is beautiful. She came in wearing a white tank top and shorts. Judging by the nipples that can seen through her top, she isn't wearing a bra today. And if you paid closer attention to her body, you'll notice a very small amount of muscle on her. She is part of her college gymnastics team and she needed to stay in shape. Her workout regime helped immensely but had the side effect of those muscles, which I think makes her even more attractive.

"Why wake me up in 7 in the morning! We don't have school!," I say angrily, still hiding in my covers, but my head is poking out facing away. "I know we don't, but I came here to tell you that Mom and Dad are going for a business trip and will be back tomorrow night. We have the house to ourselves for all sorts of fun.," Riley responded with a sultry tone to the last words of her response in my ear.

I felt shivers go through my spine. If there is one thing you should know, she's a big flirt towards me. Whenever we're alone together with nothing else to do, she often tends to spend that free time with me. It started a year ago, after my 18th birthday.

-Flashback, 1 year ago-

Before I tell you that, you need to know that for the 17 years of my life, we did a lot of things together; watched movies, played games, did homework, you name it. We did everything together, we love each other like sisters. But after my 18th birthday, things changed. She ended up being nicer towards me. Considering how kindhearted she already was, I didn't think it was possible to be nicer. I used to be bullied in school, but she repelled the bullies. After my 18th birthday, she not only repelled the bullies, she looked at them murderously, as though they tried harming something precious to her.

I didn't understand what it was, but that became clear on one night we were watching a movie together. Our parents left for a business trip at the time. While movie was starting, she had me sit between her legs, and my head resting against her bust. Her hands rested on my legs. The movie was an 18+ movie with sex scenes. I got horny. While watching the scene, I started to finger myself. I was caught red handed, though.

"What are you doing, sis?," she asked me amusingly. I covered my blushing face with my clean hand. She grabbed my dirty hand to inspect it, "Were you masturbating?," she asked me surprisingly. "I shouldn't have. I'm sorry.," I say, on the verge of tears and about to leave before she restrained me, "There is nothing wrong with it, sis. It is completely normal.," she said soothingly. "Really?," I asked hopefully. "Really. Now let me help you with it.," she said before she sucked my clean hand dry.

I moaned a little from the hand licking. Her tongue felt so good against my small hands. Riley slid her big hands towards my tiny pussy in my pants and started fingering me. I was fully moaning now. After a minute of fingering, I came on her fingers. "We'll be having lot's of fun now, sis.," she said sexily.

Ever since then, she would tease me, finger me, and eventually kissed me. We ended up doing everything women in lesbian relationships do, but we're sisters.

-Flashback End-

I didn't want to do more of our proclivities, no matter how much it pained me to stop her. I held her off for 6 months now, but she never stopped tempting me. Every minute of her teasing is tempting me to go back and continue what we did. Wait! She doesn't know I have a cock!

"Quit hiding in the blanket-" "No, wait!," I tried stopping her but she removed the blanket, revealing my bare torso. She tackled me into the bed and held both my hands above me while straddling me, "This is what you tried to hide from me?," Riley said in that thirsty tone. She used her free hand to start groping my left breast, making me moan.

She started kissing and sucking on my neck while she continued to grope me, "Please stop resisting, Anna. I love you. I want you. I want to kiss every fibre of your being, suck and squeeze your adorable tits; I want to smother your adorable face against my bust; I want to eat out your adorable pussy; there are so many things I want to do to you to show you how much I love you. The past 6 months were without touching you. Please let me love you again."

I was paralyzed by the confession. The separation was as painful for me as it was for her. I couldn't take it anymore, "I can't stay away from you any longer. I want you, too. But...," "But...?," Riley asked. "Please lift the blanket off my waist."

Riley looked at me funny before doing what I asked of her. She sees my cock, erect at 7 inches. Her expression shows shock and...lust?

"How long have you had it?," she asked. "I woke up with it. It wasn't that big before.," I say, turning away and getting ready to be called a freak. "Anna, I don't care if you are a girl, boy or futanari. I will always love you.," she said, turning my head to face her a planted a soft kiss on my lips. I closed my eyes and accepted it.

After the kiss, Riley turned her attention back to my cock. She touched the tip, making me moan and jerk my hip upwards. "Please be gentle, it is very sensitive.," I pleaded. "Really?," Riley responded flirtatiously. She ran her finger down and up my shaft slowly and repeatedly, and I was jerking my hips, moaning as she did so. My dick started twitching at faster speeds. After another minute of this, pleasurable , I came onto my stomach and tits. My hands are still held above my head.

Riley moved her head towards my torso and started licking up all of my cum from my tits and stomach, "Your cum is delicious, sis.," she said, giving my tit a squeeze. "Did your cock just grow?" Looking back at my cock, it is still erect but 12 inches in length! "It grows every time I/you cum?!" Riley and I say simultaneously. We look at each other and giggle.

"Let's see how big you can get.," she said before she grabbed my shaft and started pumping. "Sis, wai-oohhh!," I couldn't finish as I came again immediately. The feeling of her hand on my cock compared to my hand is three times better! "14 inches, eh? Anymore?," she put my cock in her mouth and started giving me a blowjob. I came again after a minute into the blowjob. She swallowed all of my cum, but didn't stop the blowjob.

-20 minutes later-

I came for the 50th time. She let go of my 20 inch cock! It stopped growing 10 minutes ago. I thought it would be as big as half my body! "I can't have enough of your cum. We have so much catching up to do, Anna. And we'll be making up for all the time lost. And your lovely new appendage just created so many possibilities.," Riley told me happily before giving my cock a kiss, then giving me a kiss. My cock started to lose the erection, reaching flaccid at 5 inches. Looks like I am a grower.

"Time for a shower! Come with me.," Riley picked me up bridal style and took us to her bathroom to shower. I was exhausted from the orgasms to argue.