Mark paced the length of his dorm room anxiously. It wasn’t a long distance, 10 or 12 feet from the door to the bathroom and back, but the movement helped. He hadn’t felt this anxious in years, and all of it over something as stupid as a girl.
A girl who was nuts about him, he reminded himself. Sitting on the side of the bed, he ran his hands over his face and through his short brown hair. Liz was super into him, totally sweet and devoted. It was normal for a girl like that to want to get physical. College is when that’s supposed to happen, right?
Mark’s self-interrogation was interrupted by a knock on the door. “Oh thank God,” he breathed, pushing up onto his feet and brushing himself off. “It’s open!”
His call was answered with the click of the door latch. It swung open, revealing a plain hallway and a young woman. The hall was long and narrow; the girl was anything but. She stood a head lower than him, wearing cut-off shorts and a loose tee that hung from her ample chest. Her skin was fair, almost pale, and her legs betrayed her body as inhabiting that narrow zone where chubby was still beautiful before leaning into that fat unattractiveness trap that so many girls fell into. Shoulder-length auburn hair framed a face as sweet as it was familiar; looking into her brown eyes was like looking into a mirror. His twin sister, Amy.
Amy’s lips curved upward in a grin and she lifted one hand, drawing mark’s attention to the little box she was carrying. “I brought drinks,” she said, stepping into the room and closing the door behind her. “Siddown and tell me what’s got you all messed up.”
Mark sat on the bed, and Amy joined him, pulling a couple coolers out of the little six-pack. She opened one and handed it to him, then took a drink from the other. “It’s probably stupid,” Mark said, staring down at the bottle in his hand. “I’m freaking out about Liz.”
“Again? Jeez,” Amy replied, rolling her eyes. “That girl is totally in love with you. What could you possibly have to worry about?”
Mark took a long pull from the drink. It was fruity, sugary… exactly the sort of thing Amy liked. Mark would have preferred a beer, but he had to respect the kick of alcohol content that followed it down his throat. “She wants to get physical,” he said finally, shifting to look at her.
Amy laughed. It was a sound as sweet as the drink had been, and it automatically put Mark a little more at ease. “Is that all?” She nudged him with an elbow. “Good for you! She’s real cute, you’re a lucky guy. Go get ‘er!”
Mark chuckled. “‘Go get her’. It’s not really that simple, is it? I mean, I’ve never done any of this before. What if I mess it up?”
Amy shrugged. “You’ll totally mess it up.”
“Seriously? Nice advice, sis.”
“…and that’ll be fine!” Amy continued. “Everyone’s first time is weird and awkward. There’s limbs and fluids and all sorts of… logistics. But you’ll be with someone who cares about you and you guys will figure it out.”
Mark smirked and took another drink. “We’ll ‘figure it out’, huh? Was that how your first time went? Weird and awkward until it wasn’t?”
Amy looked down at her hands. “Well, about that…”
Mark stared in shock. All through high school, he’d been the shy side of their duo. He did alright socially, but dating had just never really clicked for him. He’d had good times, good friends, and of course his sister was always there to hang out. Except when she wasn’t. Amy had dated a few guys, none of which had gotten too serious as far as he knew. Surely, she had at least some experience? “You’re shitting me,” Mark said after he’d processed the information. “What about that time-”
“Heavy petting at most. I’m almost as lost as you. I just hide it better and have a bunch of secondhand knowledge.”
“Well, that’s… fuck, Amy, I mean I’m glad cuz none of those guys were worth you, but still… it doesn’t really make me feel better about Liz. What about Greg?”
“Greg and I only just started dating. I don’t know if it’s serious yet, it’s just some fun times going places.”
Mark felt a sudden relief at that. Greg was Amy’s current boyfriend, and Mark had never cared much for him. Something about him was just off-putting, like a really great-looking pizza that turns out to have a ton of grease on the crust.
Amy shrugged. “Anyway, what’s going on with Liz? Exactly?”
Mark shrugged. “Well I mean, we were making out last night-“
“Nice.”
“Shut up. We were making out, and she was all up against me then she tried to undo my pants.”
“Awesome. She knows what she wants. What did you do?”
Mark closed his eyes, thinking back. He could still see her hand, could hear the zipper moving down… “I told her to stop. I said I wasn’t ready.”
“I knew it was coming and I’m still disappointed,” Amy replied with a sigh. “I get it though. It’s… it’s a lot. I’ve done the same thing a few times.”
“But I want to,” Mark blurted. “I really want to. I was so hard, if she’d go my pants open it mighta broken her wrist!”
Amy laughed again. “Oh my god, Mark. I love you so fucking much.” She leaned over and took his hand. Her grip was warm, soft but firm. “I’m super excited for you. This is gonna be easy. Just next time, don’t stop her. She knows what she wants.”
Mark frowned. “Yeah, I guess…”
“You guess nothin’. You know. She’s gonna make it easy and after you’ll feel better.” Amy let go of his hand and passed him another cooler. His first one was empty somehow, although he didn’t remember drinking it that fast.
There was another problem, though. Mark frowned and took another drink, screwing up his courage. “What if she doesn’t like what she sees?”
Amy scoffed. “Dude. Look at you. You’ve been working out for two years. You’re hot.”
Mark felt himself blushing at the compliment. It was true, he’d really gotten in shape the last couple years. But to hear a girl say it was something else. “Thanks,” he replied. “But I wasn’t really talking about that.”
“Oh.” Amy paused for a moment. “OH!”
“Yeah. ‘Oh’. What if she whips it out and, like, she thinks it’s weird or too veiny or, like, gross and funny-looking?”
“Mark, all penises are gross and funny-looking. Penises? Penii? Penises.”
“Not helping, Ames.”
“Sorry! Sorry. But it’s true! They’re all so weird, like alien arms or something. But that means yours is no weirder than any other one, right? Every guy has one.”
Mark sighed. “Yeah, I guess. I just wish…” He stopped and turned toward his sister again. “I have an idea.”
“Oh god. I don’t like the sound of that.”
“No, really! Okay listen. You’re a girl, right?”
“…yes…”
“Right. So, what if you just… you know, look at it? You can give me an honest reaction.”
“What.”
“C’mon Amy, you said yourself, every guy has one. And if you’re not used to it too then maybe that’ll help with your situation.”
“I don’t have a ‘situation’. I’m a virgin, and I’m okay with that for now.”
“Alright, fine,” Mark said, showing her his palms. “But you could at least help me, right? Just, you know, take a look, tell me what you think.”
Amy glared at him for a long moment. “Alright, fine. Sit over there.” She cocked her head toward his desk and chair. “I’ll look. Once.”
Mark grinned. “Okay. Hang on.” He pushed off the bed and spun the chair around to face her, then sat down. “You ready?”
“Yeah, I guess.”
Mark’s hands didn’t even shake as he undid his zipper. It was almost weird how calm he felt, pulling his cock out. He’d barely even realized how hard he was until he had to shift to clear his boxers, exposing the entire length of it to his sister.
“Jesus Christ,” Amy breathed. “Uh, I mean… okay. It’s fine.”
Mark frowned. “What’s wrong? It’s weird, isn’t it?”
Amy shook her head and looked away. “It’s definitely not weird. It’s just not what I was expecting.”
“How do you mean?” Mark wrapped one hand around his shaft, holding it. It covered less than half of the length. “Is something wrong with it?”
“No, it’s just… it’s a little bigger than I thought. It’s bigger than any other one I’ve been in contact with.” She swallowed and changed her voice to the mocking tone she used to defuse tension. “Put it away before you put my eye out.”
Mark chuckled. “Define ‘in contact’. I thought you were a virgin?”
“Well yeah, but I’ve fooled around a little, you know, hands stuff.”
Mark felt a throbbing in his grip at the mention of that. He imagined Amy making out with some boy, her hand down between them and pumping in his pants. It was an intensely exciting visual. He let go and wiped the sweat from his hand on his pant leg. “When… when was this?”
“Well, you know, like in the movie theater with- oh my god I think it just moved!”
Mark glanced down. He could still feel the throbbing, and down it was occasionally twitching as his pelvic muscles reflexively clenched. “Yeah… well, it’s pretty worked up. I’ve got a date with Liz tonight, and I’ve been obsessing… jeez, I’ll probably explode as soon as she touches me.”
Amy giggled into her hand, apparently getting a visual of her own. “Sorry! Um… you should probably ‘relieve yourself’ before you see her. It might help with the… exploding… and will probably relax you.”
“Oh jeez, good idea.” Mark wrapped his hand around himself again and started slowly pumping.
“Oh my god, Mark!” Amy started to get up off the bed. “At least wait til I leave the room!”
“No!” Mark barked, making her freeze in place. “No,” he repeated more gently. “Stay. Let me look at-“
Amy frowned. “Gross, Mark. I’m your sister.”
“Yeah, but if I didn’t know it was you, I’d enjoy looking at those bare legs,” he replied. “Those hips, that- you’re beautiful, Ames. Own it.”
Amy blushed visibly. “I’m still your sister.”
“Please? I won’t look at your face, I promise. You’re helping me so much, getting used to seeing a live girl’s body.”
Amy sighed and sat down again, crossing her arms and looking away. “Fine. Just don’t make it weirder.”
“Thanks.” Mark let his eyes drift up and down his sister’s body, slow stroking himself. She was everything Liz wasn’t. Shorter, curvier, smarter… Liz was a sweetheart, but damn if she wasn’t a little dim. Amy was clever, sarcastic… engaging with her was like a fencing match, while with Liz it was more like taking a dog for a walk. And those thighs, pressed shyly together, hiding a secret… a warm chill rushed up his spine. “Open your legs,” he commanded.
Amy flinched. “What?”
“Open your legs, please,” he repeated more gently. “I want to see better.”
“Okay, fuck this.” Amy shifted to try to stand up again.
“Amethyst Catherine Warnke, sit down,” Mark commanded. Amy sat immediately. “Open your legs a little. Good girl.”
Amy’s face turned a few shades redder. “Just… just hurry up, okay?” she asked, voice much smaller than before. Suddenly she was that little girl he’d grown up with, the one who was totally independent from anyone except for him. Her thighs opened, revealing the curve of her cut-offs pressed tight against her mound. Mark imagined the heat that was there, the softness of her thighs wrapped around him, the soft moans of her voice as she lost herself in pleasure.
“Oh fuck,” Mark groaned as the sudden pleasure shot through him. His hand pumped faster, and he felt his muscles tighten, urging his hips to thrust as he shot long, thick ropes of cum with a force he’d never felt before. It splattered on the floor, the bed, and across Amy’s leg.
“You asshole!” Amy cried, shooting to her feet. She clutched at the bedsheet and started wiping her leg. “I can’t believe you!”
Mark chuckled, running his free hand through his hair. He was sweating. “Wow. That was intense. Sorry.”
“Ugh. Let’s just never talk about this, okay?”
“Sure, Ames. Sure.” Mark grabbed some tissue from his desk and wiped his hand. “Seriously though. I feel so much better. Thank you.” He stood up and opened his arms to hug her.
“Mark.”
“What?”
“Put that thing away first.”
Mark chuckled. “Sorry.” He tucked himself back into his pants and pulled her in for a tight hug. Her body was warm and soft. Her shampoo wafted into his nostrils, some sort of cherry scent. He could feel a stirring in his pants again already, but Amy didn’t seem to notice; she relaxed into his arms and sighed.
“Look, just… just be yourself and relax. Okay? You’ll be fine.”
“Yeah, okay.” He let go and grinned. “I love you, you know.”
“Yeah, yeah. I’m going to go shower. Have fun with Liz.”
Mark couldn’t help but watch his sister’s ass as she left. He’d admired her body plenty of times before, but now he felt like he was seeing her in a whole new light. He’d certainly never gone that far into fantasy about her. He expected to feel weird about it, but instead he felt relieved. Like a weight was lifted, and a door opened.
As soon as the door closed, he turned toward the shower. Time to clean up for tonight. After all, Liz was expecting him.
Source: reddit.com/r/sexystories/comments/b70yax/mf_m_mast_inc_stretching_the_old_writing_muscles
I’ll set up a metapost on my subreddit once I get some more chapters written. I’d love some feedback on this! I missed you guys.
So far so good!