My name is Ben Harker. I’m one of the Forester Five, the group of kids you probably read about in the paper a decade ago. We were five unrelated kids born on the same day across the world and given up for adoption. Some billionaire-funded research group swooped in and took us for these strange experiments. They gave us weird drugs and monitored us day in and day out. To this day, no one knows the purpose of these experiments or the full extent of the physical or psychological effects they had on us.

The whole thing was exposed when we were still children. To be honest, I don’t remember anything from those days. After the Forester thing blew up, Natalie and I were adopted together by the Harker family. We never knew the names of the other Forester children, and all of our names were kept confidential in the news.

Growing up, Nat always made a point to tell people we were adoptive siblings, as if being related to me by blood would somehow sully her popular reputation. Throughout high school, the boys saw her as the innocent girl-next-door with the long brunette hair and irresistible smile; while the girls saw her as the popular bitch who developed big tits and thick curves and knew how to use them to win anyone over.

I was, of course, always in her shadow. The tall but unimposing nerdy guy. I survived high school by getting the best grades I could, playing video games with the like-minded friends I did have, and staying out of the way of the asshole jocks.

At 19 years old, I was now ready to make college a different story. My style was a little less awkward nerd and a little more… hipster geek? At least I hoped it was. I had never had a girlfriend and I was sure I was going to be the only guy in my year who had never had sex.

Ben Harker: shy, nerdy, virgin. What a hand I was dealt.

Natalie and I started college at the same time. But midway into the first semester, she withdrew from all of her classes. Something wasn’t right with her. She had always been a heavy sleeper, but those days she could sleep for weeks if you didn’t wake her. Even when she was awake, she was too lethargic to focus. It was like her body was trying to force her into a coma.

She had been seeing a new specialist and things seemed to be improving. She had been sleeping normally for most of the past week, so something must have been working.

I was studying for a midterm when she knocked on my bedroom door, walking right in before I could say “Come in!”

“Hey Ben,” she seemed uncharacteristically nervous. “Can I talk to you for a minute?”

“I guess so,” I swiveled around in my desk chair and gave her a cautious stare as she sat down on the foot of my bed across the room.

“You know how I’ve been seeing that new specialist?” I had never heard her talk this way, she was so quiet. “Well, she’s figured out what’s going on with me.”

“That’s great!” I shot out of my chair and joined her on the bed, excited for my step-sister even though she was a brat. “What is it? Is there a treatment?”

“That’s the thing,” she started. “She thinks it has to do with what happened to us at Forester. She got a hold of a bunch of their research and… I have this rare condition. My body doesn’t produce enough of something and because we were in those experiments together, yours overproduces it.”

“Alright, so do I give you some of my blood or something?” I asked. “I promise I’ll do whatever I need to.”

If I had known what whatever was, I may have been more hesitant to make that promise.

“It doesn’t transmit through blood,” she sounded defeated. “Believe me, I asked if there were any other way. It can only transmit through…”

She hesitated, closing her eyes and sighing deeply, like she couldn’t believe what she was about to say.

“Sperm.”

I swore I had misheard.

“Like sperm sperm?” I repeated. “Cum? My cum?”

"Well I'm not psyched about it either Ben!" there was her usual fire. "I know you're up here in your room jacking off half the time anyway."

"I am not," I lied. "But if this is what you need then fine. I can... I don't know, freeze some for you. How often do you need... it?"

"She wants me to start on one dose a week"

Dose, I rolled my eyes. This was the most bizarre thing that had ever happened to me, and I was kidnapped as a baby and experimented on by a billionaire-funded research team.

"But it can't be frozen, " she added. "It loses it's potency so it has to be... fresh," she shivered as she said it.

We both took a deep breath, there was a long pause as we looked at each other waiting for the next person to say something. Nat finally broke the tension.

"So I'm thinking you can... you know, yourself. I'll wait outside and when you're done I can just come in and get the dose."

"Fine, but don't go telling anybody about this," I took on a stern tone. "This better not be like high school where you take every chance to make me look like a weirdo."

"Do you think I want people to know about this?" She fired back. "This stays between us forever."

"Deal."

"Well," she got up, noticeably more confident with all of that off of her chest, and made for the door. "No time like the present. I'll be back in - how long do you need? 30 seconds?"

She smiled back at me as she left and I shot back, "very funny."

I laid down on my bed, shifted my pants down to my ankles and put my cock in my hands. I tried to think of something else, anything other than my step-sister. I tugged on my limp dick, but I couldn't get the thought of how ridiculous this was out of my head.

There was a knock at the door. "Hey, are you almost done in there?"

"Seriously, it does take me longer than 30 seconds," I shouted back.

"It's been like 10 minutes!" Her muffled voice shot back through the door.

I must have been concentrating so hard that I completely lost track of time.

Without warning, Nat opened up the door and let herself right in. She rolled her eyes and scoffed as she saw me, pants around my ankles, lying on the bed with my half-hard cock in my hands.

"Are you not even hard?" she cracked a judgmental smile.

"I'm having a hard time getting in the right mindset here, okay?" I protested.

"God, if you want something done right, you have to do it yourself." She muttered under her breath. "Let me help you get this over with."

I slid back on the bed. "I don't know Nat. I'm not sure I want my first time to be with you."

She let out a condescending laugh. "Me neither! Never. Oh my god!" She held back more giggles. "I'm just going to use my hand."

"Well," I started to blush and turned my eyes away from hers. "I've never really done that either... with someone else."

She stifled more giggles, clearly feeling a little sorry for me at this point.

"That's alright," she regained some composure. "Just let me take care of it."

She cautiously placed her hand on the base of my cock, letting her fingers run through my pubic hair as she traced her palm to my shaft. Lightly gripping it, she began to stroke back and forth. The rush of feeling another person's hand on my cock almost made me forget that it was my step-sister's. I felt an electricity run from her hands through my body, like that rush you get when you accidentally brush hands with your crush, it crawled all through my legs and up my spine.

Before long, I was rock hard. I had masturbated plenty before, but I had never felt myself so overwhelmingly turned on. My cock was pulsating and writhing with every stroke of Nat's soft hand.

"Are you alright?" Nat asked, a hint of concern and impatience in her voice.

"Yeah, it feels incredible!" I probably sounded like a total dork.

"Oh," she looked back down at my stiff cock. "Is that as big as it gets?"

Any ego I had accumulated from the last few minutes of a girl touching my dick for the first time just completely sank away. I was embarrassed, but something about Nat's teasing no longer made my skin crawl - at least not in the same way.

"It's not that small," I defended weakly. "It's totally average..."

"I guess," she must have realized this was not the most opportune time to discuss my dick size, but continued nonetheless. "I just expected it to be a little larger based on other guys I've done this with."

She continued to stroke it and I couldn't help but moan in response. I should have been offended or turned off, but instead I just felt a flurry of heat. Torrents of precum oozed out of my cock, drenching Nat's knuckles as she kept stroking up and down.

"I can't believe you're moaning," Nat teased impatiently as she stroked faster, "can you please just hurry up and cum?"

This was clearly all business for her, she wanted to get it over with.

I felt myself grip the sheets as Nat's hand slipped up and down my wet cock. I could feel my shaft tighten as I prepared to cum, closer and closer to losing control.

"I'm gonna cum!" I managed to muster.

Nat positioned herself directly below my cock with her mouth open and her tongue out, ready to catch the "dose" she needed. I knew she was just doing this because she had to, but watching her work my cock in anticipation of my cum was... exhilarating.

As I inched toward climax, Nat placed the head of my cock directly on her tongue. Feeling my cock pressed against the warm wet surface of her tongue, seeing how agonizingly close the tip of my cock was to her lips, sent me over the edge and I came hard. A river of my cum ran directly into her mouth. She winced a little as she tried to catch it all in her mouth and lap up any stray drops.

An air of silence fell across the room as I slouched back into the bed. Nat got up, flipped her hair back to re-position herself, swallowed and smacked her lips together like I had left a poor taste in her mouth, and walked out of the room without saying a word.

I had no idea how to feel. Were things going to be weird between us now? Yes. They had to be! Are we going to have to do this regularly? I thought. Well, at least for the foreseeable future...