Ruby Rose, Her New Cock, and an Ero System (A LitRPG RWBY AU)

6. Carried Away

The safe room was just barely wide enough to sleep shoulder-to-shoulder, so at least they wouldn't have to spoon all night. Not that Yang would've hated playing big spoon to Ruby, but considering their nudity and the events of the day—particularly that bit in the hole, with Ruby rubbing her cock against her stomach—the less touching skin between them, the better.

There was a lock inside the room, which meant a safe, uninterrupted night's sleep. The only question was how long it would take to knock out when Ruby was laying on her back right next to her, twelve inches of cock proudly on display.

Surprisingly, unconsciousness came easy. She'd wrung herself dry, both aura and muscles. Bone-deep exhaustion was a great way to put a person to sleep.

Some time later—probably a few hours—Yang was woken for a reason she didn't immediately place. It took her a second to recognize what had stirred her as she blearily blinked her eyes open.

Something was poking into her leg.

Specifically, something thick, hot, and round was poking at the back of her thigh.

Yang's mind went blank.

Worse—or better?—that wasn't the only thing she became aware of. While she'd been asleep, she and Ruby had repositioned from their shoulder-to-shoulder, on-their-backs orientation. Now, Yang was turned over on her side, facing the door. From how Ruby's arms were wrapped around her stomach, cuddle-bugging into her, Yang had ended up the little spoon rather than the other way around.

Which, of course, made the hot, blunt thing bumping between her thighs…

Her little sister's cock.

And it wasn't a gentle poke. Not just brushing against her. Ruby's hips were wiggling around. In fact, as Yang's melting-down brain was realizing this, the movements became even more than just 'nudging.'

Ruby pushed her hips forward with force, and, with both Yang's thighs and Ruby's tip lubricated by precum, she finally succeeded in her goal: she slid between Yang's thighs, cockhead popping through the other side. Behind her, Ruby let out a little moan of delight.

Ruby…

Was fucking her thighs?

Yang had woken up to her little sister fucking her thighs?

There were a lot of reasons Yang's brain simply stopped working. Not least was the visual, looking down her body to see several inches of cock sprouting from between her legs. And not just sitting there, staying still, but moving. Even as Yang failed to understand what she was looking at, it pulled back, disappearing into soft skin, before pushing back out—a soft, slow, gentle impact on her ass joining its reemergence.

Yang never thought she would know what it felt like to have Ruby thrusting into her, but here she was.

Feeling that.

Experiencing her sister fucking her.

She froze, incapable of thinking, much less moving, as Ruby picked up speed. She was going slow—very slow. But each thrust had her cock working higher up. Closer and closer to something dangerous.

Until her next thrust had her cock rubbing straight against Yang's pussy. Ruby let out a shaky breath into her ear. Yang stared down her body, disbelieving, at the glistening member resting against her pussy. Now wet. Lubricated with more than just precum.

Because she was wet. Wet for her little sister's cock, and she'd gotten it nice and slippery to make the thrusting even easier.

Which Ruby took advantage of. In and out. In and out. Each motion accompanied with a soft—but growing louder—clap against Yang's ass. And not just that, but Ruby's hands started to creep up from where they were hugged around her stomach. Without an ounce of hesitation, Ruby grabbed her tits and squeezed, moaning.

What the hell was happening?

Yang snapped herself out of the shock, and other seizing emotions that definitely weren't shock.

She looked over her shoulder.

Only to see…

That Ruby's eyes were closed.

Holy shit.

She was sleeping?!

Ruby hadn't decided to use Yang's body as a plaything overnight, to wake her up with a surprise cock between her legs, she was just…

Sleep-fucking?

That made sense, ridiculous as it was. If Ruby tried to fuck her, then—

Well, first off, she wouldn't try to fuck her, because they were sisters.

But if she did, it sure as hell wouldn't be like this. With Ruby just deciding to while she was sleeping.

Again, not that Ruby would ever try to fuck her. Under any circumstances. But if she did, it would be more romantic and consensual than that.

The realization that it was an accident changed nothing. Ruby's hands were still groping her from behind. She was still thrusting between her thighs, and by the sounds of her labored breathing, getting closer and closer to the edge.

Who the hell sleep-fucked? Just what kind of libido was Ruby dealing with? The constant erections made more sense now.

Maybe Yang had been a bad big sister for ignoring what Ruby was going through. Just, what was she supposed to say, when it came to these bizarre circumstances? She sure as hell didn't have much advice to give on how to handle a cock. She'd never had one.

Didn't matter. Yang had to do something about this.

So why was she just lying there and letting it happen? Why did she stay frozen and let Ruby have her way with her?

Probably because, holy shit, Ruby's cock felt good. It burned a pulsing, throbbing heat in between her thighs, and each stroke rubbed a hard, veiny mass along Yang's pussy, making her entire stomach clench, clit tingling with a fire she'd never experienced.

To think if Ruby were to take just a slightly different angle… or even if Yang were to reposition just a bit… her next stroke forward might end up with Ruby's cock going somewhere it wasn't meant to.

Easy as that, it could happen.

For the first time, Yang wondered what Ruby would feel like inside her.

That massive cock stuffed deep into her pussy, stretching her wide, reaching where nothing had reached before.

Why was it the hottest thing she'd ever imagined? Why did her pussy clench at the thought of her little sister inside her?

S-She had to stop thinking about this. It was wrong. It was Ruby.

Swallowing thickly, she forced herself to move. She couldn't just let Ruby use her thighs to completion, as easy as it would be to lie there and pretend she could be absolved of responsibility, since 'she wasn't actually doing anything.'

Reluctantly, though she would never admit reluctance, Yang wiggled forward, pushing back with one hand on Ruby's stomach to slide her away.

Ruby whined at being denied, a frustrated pout instantly appearing on her face, but somehow staying asleep. Her hands grasped to pull Yang back in, but she firmly stopped her.

At the less-gentle touching, Ruby's expression morphed—clearing, then changing to confusion. Her wiggling-around stopped, and her eyes blinked open.

Yang was lying on her back by then, and so was Ruby. Back to their original positions. Ruby was breathing hard. So was Yang, she realized.

Silver eyes met Yang's. Then they flicked down to her erect cock. Ruby's glistening, lubricated cock.

Wow. Had that all been Yang? Enough to fully coat her like that? She must have been even wetter than she'd realized.

Ruby's reaction wasn't what Yang would've expected. Not instant, red faced stammering as she tried to come up with an excuse. Instead, her mouth fell open, and she started to pant. Her cock twitched, once, hard. Then a second time. A droplet of pre landed on Yang's leg. That damn thing had some power in it. A tool meant for a proper breeding.

A…tool meant for a proper breeding?

Please never think that again.

"Y-Yang," Ruby said. "It…it feels really hot, right now." She bit her lip and groaned, her hips wiggling side to side, making it bounce around.

To be fair, Ruby had just been interrupted from an indulgent thigh-fucking session. Ruby didn't seem to have realized that, but her body's frustration, at least, had gone nowhere. Her arousal had leaked into her head too deeply to ignore. Ruby wasn't even being Ruby, completely shameless in that moment.

"Yeah," Yang said, trying to maintain her cool. "Woke me up by poking it into me, you know."

"D-Did I?" Ruby didn't seem to recognize what Yang had said, not right away. It took several seconds to digest, before she blinked and faced Yang. "Wait, I—?"

"It's fine," Yang hastily said. "But, uh. Brings up a good point. I think you should take care of it." She shrugged, over-casual. "Not healthy to ignore your needs, right?" And if she did, Yang might wake up to a different sort of sleep-fucking. One much more dangerous than just her thighs.

"What?"

"You know," Yang said. She mimed a crude gesture. "Take care of it. Else you're gonna keep getting more pent up."

She wasn't sure how she could talk about this with a straight face. Doubly so when there was a hot pulsing down between her legs, her own frustration from having pushed Ruby off her. Fuck, had she really needed to interrupt Ruby? She could've just laid there and let it happen.

"You…you want me to—?" Ruby asked. "To—?" She mimed the same jerking off motion, silver eyes wide.

"Someone's gotta. And I assume you're not volunteering me," Yang joked.

Ruby's eyes widened even further. Maybe Yang shouldn't be joking about jerking her little sister off. Especially in the hot and muddled state Ruby was in. Hell, that both of them were in. Yang was just better at playing it off.

"Pressure's building, and you gotta release it," Yang continued. "Simple. So go ahead. No big deal. We're in a weird situation, and it's gotta be dealt with. It's just me, don't worry about it. No judgment."

Yang would've thought Ruby would protest. But again, she had underestimated the hazy condition Ruby was in. She held Yang's eyes briefly, then looked down her body—still lying on her back, not having moved much.

Her hand went to her cock.

H-Holy shit.

Yang had intended to offer to turn around, and for them to each take one half of the tiny room to themselves. Give Ruby some small amount of privacy. Maybe even head out into the dungeon, if she seemed uncomfortable.

But nope.

Ruby needed relief too badly.

Right in front of Yang, she reached out and gripped that big, fat cock of hers. Her eyes fluttered closed and a groan of satisfaction wrenched from her lips. She started to stroke. Up and down. Grip traveling in a slow, exploratory manner, hips arching the slightest bit as her hand reached her apex. Then went back down.

Already worked up from using Yang's thighs—even if she didn't remember it—Ruby's movements grew faster with mounting desperation. Thick, wet sounds filled the air as her fingers, thanks to the lubrication, slid easily up and down her cock.

Thanks to Yang's lubrication.

She was using Yang's wetness to jerk herself off. That realization hit her like a wrecking ball. All at once, her core went from simply throbbing to outright on fire.

She'd never felt so hot and sensitive. Every breath fanned her arousal higher, the air sweltering and cloying around her. Swallowing thickly, Yang tried to look away, but couldn't.

The slick sounds of Ruby jerking off continued, a constant, lewd staple in the air. Her little sister's breathing grew heavier, panting loudly. Her hand moved faster. A second joined it. And even that wasn't enough to cover its ridiculous length. Ruby's hips started to buck against her fists, movements growing frantic.

Yang's entire body willed her to crawl forward, to take over the task. A good big sister would help Ruby navigate this, right?

But no, Yang wasn't that far gone. She knew how wrong that idea was. As hot as she felt, and as much as her stomach was clenching, Ruby was still family. Her sister. Her little sister.

Yang's brain scrambled for a rationalization. It wasn't that she was lusting over Ruby. Just that big, fat cock of hers. That gorgeous veiny bitchbreaker that would tear her in half in the best way possible. Bring her pleasure in a way she'd never experienced. But not Ruby herself. Nope. Not at all.

Yang wrenched her thoughts back into order. She had to stop thinking about it.

But seeing how she couldn't tear her eyes away, that wasn't going to happen.

As Ruby's hand sped up, her flush deepened. Yang's eyes drifted to the expression on her little sister's face. The raw lust there. Her mouth was open, and she panted with every movement. Not just that, but her thighs were spreading bit by bit further apart. More lewd, more brazen. Not for her audience. Just for her own pleasure. Her own satisfaction.

She pumped her hips vigorously, thrusting into her fists as much as she was jerking herself off, now. She was getting close. Her breasts shook with the eager motions as she rocketed toward her peak. Did Ruby even know what a sight she made? Probably not, lost in her haze of pleasure.

But that locked-in, single-minded lust on her face conveyed how good it must feel.

Up and down. Up and down. Over and over.

And, finally, with one last frantic increase in pace, Ruby's entire body tensed, and she came. Her back arched as her hands jerked rapidly along her length, stroking herself with a desperation Yang had never seen. Milking her hard-earned reward out.

Her cock twitched again and again. Every thrust of her hips up, warm ropes sprayed from her cock. Those strands flew through the air in random directions with how jerkily she was stroking herself.

Only then did Yang realize there would be consequences to cumming wildly inside a confined space. Spurt after spurt, Ruby's orgasm kept going. She milked herself out all over herself, her surroundings, and, of course, Yang.

Collapsing on the ground, Ruby breathed out a long, low moan, melting into a blissful relaxation. Yang, still frozen, feeling ropes of Ruby's hot cum over her face, tits, stomach, and legs, lay there with wide eyes—as Ruby, exhausted from her first cock orgasm, fell asleep right then and there, without a word of commentary.

Well.

It looked like she would be finishing the night with her little sister's cum all over her. She…couldn't say it was the worst fate in the world. The ache between her legs, which she had to ignore? That, though, was up there.

Because there was no way she would be finishing herself off. That would be admitting how aroused she was by her little sister's display.

And she most definitely, certainly, absolutely, was not.