Cave Johnson stood outside Aperture Science's multiverse machine—or, rather, he paced outside it. He hated waiting for things, hated not having anything to do, and already twenty minutes had passed since Caroline had left him. She was on a quest to find the filthiest, most sexually-deviant version of Cave Johnson possible. Surely it shouldn't have taken her too long.

Caroline had first made the suggestion as a joke, dropping it casually into conversations to test his reaction. When he hadn't immediately paled at the thought, she started to mention it more and more, nourishing the seed she'd planted in his mind. As Aperture perfected its multiverse machine, she perfected her proposal, until Cave was sure it had been his idea all along. Cave Johnson was going to use science to his advantage. Cave Johnson was going to face a challenge other men would never approach.

Cave Johnson was going to have sex with himself.

Of course, Caroline was always forward-thinking. She knew how her boss was when it came to anyone who was different than the norm. Science was allowed to broach all kinds of physical barriers, but when it came to social issues, Mr. Johnson was…narrow-minded. There weren't likely to be many versions of him who would be willing to take on this kind of experiment, whether it was for science or for pleasure.

Fortunately, infinite universes lead to infinite exceptions. After a few more minutes of pacing, the portal opened, his determined assistant striding through it—and of course, she wasn't alone. In her soft hand was a strong, masculine one, the hand of a blindfolded Cave Johnson.

The unblindfolded Cave stepped back as he took in the newcomer's appearance. This version of him was young, much younger than he, and the experience of seeing his past before him was…disconcerting. Thick, well-kempt hair framed his unlined face, and he'd only just begun to carry the extra pounds that now padded the older Cave's body. He was a handsome devil—Cave couldn't deny that—but if it was possible for the CEO to feel intimidated, now was the time.

On the other hand, Cave Johnson didn't back out of anything. Ever.

"C'mon, kiddo—you can't make me wait forever," said the clone. The younger man didn't appear to know that he wasn't alone, directing his voice only to the woman towing him off of the multiverse machine. "What's this surprise you've cooked up?"

"Just one more minute, Mr. Johnson," cooed Caroline. Cave—the real one, not the blindfolded imposter—bristled at his assistant's patient tone. That was the tone she used with him, not…him? Goddammit. He hadn't expected this to be so confusing.

Caroline sat the hostage on an armchair in the middle of the room, acting more gently than Cave would have liked. With a few cords she'd gathered earlier, she tied his arms and legs to the chair. Cave's double chuckled. "Well, I'm starting to see where this is going…"

"Oh, Mr. Johnson!" She finished securing the alternate in place with one last tug. Stepping back, she gave Cave a questioning look, as if to ask if he was ready. Of course, he wasn't, but he wasn't about to let that stop him. Summoning his strength (or at least his stubbornness), he nodded to signal his consent, and Caroline removed the blindfold.

There was a beat. "Huh." The clone looked him over, his gaze piercing. "Looks like you found one handsome devil—didn't know you were into old guys, Caroline. But maybe you're just into me!" He gave a barking laugh that sent chills of familiarity down Cave's spine.

"Yes, sir, Mr. Johnson," Caroline chirped, stepping from behind the foreigner and sliding her arm along the real Cave's waist. He held her possessively, staring down his double. The other looked back and forth between them before, finally, realization seemed to set in.

"So…you're his Caroline."

"I sure am!" Her voice engulfed Cave in warmth. Damn straight, she was his.

"Huh." The man looked a little sulky, which only fed into Cave's sense of superiority. "Then…why the hell am I tied up here?"

Caroline looked to her boss, as if waiting for him to answer. It was probably a smart thing to do—she couldn't go around stepping into his big moments—but in this case he was at a loss for words. After all, he couldn't very well tell this stranger that he wanted to fuck him. The double might think he was gay or something.

"Come on, spit it out. If you're looking for secrets, you're not gonna get 'em. Build up your own company on your own terms—my Aperture is mine." Cave felt a wave of indignation at the stranger's words—what did he think this was, Black Mesa?—but before he could rage at him, the man continued. "But if you're looking for sex…well, that's another story."

Christ. Was it really that easy? Was this version of him that eager to have sex? Cave, of course, didn't bother to consider that he was the one pursuing the stranger. It was clearly the other man who was out of the ordinary.

Caroline had done excellent work.

"So, what is it, handsome? You brought me all the way here to suck me off?" The man glanced down, causing Cave to follow his gaze—right to his foreign, bulging crotch. "If that's the case, I'm happy to oblige."

Cave swallowed hard, though his mouth had gone dry. It was starting to dawn on him that this was actually going to happen. This was real—and he wasn't at all ready. But he wasn't about to let this imposter know that. He summoned his best domineering tone and addressed the man.

"That's not how things are gonna go down. I'm not going anywhere near that…thing between your legs. I'm the one in charge over here. You're just a…a cheap copy. I get to decide what goes on between us, and I say I want a blow job. If you so much as hand jive with yourself, you're going right back where you came from—or worse."

The other man looked up at him, only the briefest of moments passing before a smirk crossed his lips. Cave's heart fluttered at the expression; he was striking. "All right," said his alternate at last. "You're in charge in this universe—as much good as that does you. I'll play your game. I'll make you cum."

Cave couldn't tell whether that was a promise, a challenge, or a threat.

"And what about you, princess?" The man's eyes were trained on Caroline now, tracing her body in a way that made Cave see red. "You gonna come along and play with a couple o' Johnsons?"

Caroline, to her credit, didn't fall for the line—though her cheeks did look a little flushed. "Oh, no, sir," she said with a giggle. "I'm just here for observation." She gestured to an empty viewing area over the room, where scientists usually stood to make notes about test subjects.

Cave's double pouted, though he didn't look that upset. "Up to you, kitten. But if you ever wanna have an experience with a real man—"

"She does. Every damn day." Cave found himself nearly snarling at the stranger, who merely smirked up at him. "Learn a little goddamn respect."

"Get your pink little panties outta that bunch. I'm just sharing my view of things."

Before Cave could tell the double just where he could put his view of things, a pair of soft lips landed on his. He melted instantly into the familiar, feminine embrace—Caroline's embrace.

When she ended the kiss, she was still in his arms, beaming up at him. "Thank you, Mr. Johnson." Her expression, earnest and bright, renewed his determination. He was going to do this—for her. "I'll be watching."

Her lips brushed against his cheek before she left the room and situated herself behind glass. He and his double were, in one way or another, alone.

"Well? What are you waiting for?"

That, Cave thought, was a good question. He began to unzip his pants, but his clone's voice interrupted him.

"Hang on. Aren't you gonna untie me first?"

Cave frowned. Why the hell would he untie some freak from the multiverse?

After a pause, the man nodded. "…Right. I get it—bondage is fun. Look, I'd love to stay tied up for a few hours, but we're a tall guy and the height level's all wrong. Unless I'm on my knees, this isn't gonna work. Plus, it'll be a lot more fun if I can use my hands."

Cave considered the matter. If he was going to go through with this, he might as well have the whole experience. Why should basic safety take a front seat to perfection? Still…he was starting to get an idea that would sweeten the pot. "Fine. But your clothes are mine 'til you're done."

The man barely reacted—which was a little disappointing. "Fine by me. C'mon—my wrists are getting sore."

"Get your pink little panties outta that bunch." Cave couldn't withhold his sneer, but he slowly approached his double. His hands trembled a bit as he worked to untie the bonds—from cold, he told himself, not from nerves—and Caroline's fine tying skills made the job take a little longer than it should have. He found himself leaning over the stranger, inhaling the subtle scent of coffee and expensive cigars. He smelled like…well, like Cave. When the man was free from his bonds, Cave barely gave him a chance to flex. "Strip. Now."

"Feisty." Despite his words, the man did as he was told. The layers of clothing came away, revealing taut muscles underneath. Cave had never been a bodybuilder, exactly, but he'd been in good shape in his younger years. The flat plane of this man's belly sent a strange flame through his own. Cave Johnson was extremely attractive.

When his double's underwear hit the ground, Cave found himself quite fixated on the man's member. It was thick, cut, a carbon copy of his own—and already quite erect. He wasn't sure if he felt aroused or merely bemused at the strangeness of the activity.

"Nice, right?" Cave's head snapped up at the man's teasing tone. Well, he had been staring. "This is the part where you show me yours."

"This is the part where you shut the hell up and get on your knees." Ah, there was that old Cave Johnson confidence. It was like a soft blanket, feeding his energy going forward. The fact that his double was laughing again was inconsequential. He still had the upper hand.

"All right, all right." The man obediently knelt on the floor, gazing up at Cave with an aggressively charming smirk. "C'mon, let's see it."

Cave rolled his eyes and undid the fly of his pants. He wasn't about to put in any effort in stripping for his duplicate—alluring as the man was. With a shove of his boxers, his cock was free, peeking over the pants that he hadn't bothered to push to the ground. Incidentally, his length was also erect, precum pooling around the tip.

"Not bad." The man was looking at him hungrily, enough so that he felt his ears go red. "Not bad at all." Before he could boast about how it was much better than 'not bad,' his double had shoved Cave's cock into his mouth.

"A-ah!" Cave's knees buckled from the sudden onslaught of sensation, his cock completely enveloped between the other man's lips. His double had slid the full length of the shaft down with the confidence of someone who had done this many times before. Cave couldn't fault the man; impatience and eagerness were the Cave Johnson way. Besides—he liked how it felt. None of that pussyfoot beating around the bush bullshit—just instant gratification.

After a few swift strokes, Cave's double backed away from the member, looking smarmy as ever. "Need me to slow down?"

"Shut up." This man's mouth was better used for blow jobs than for talking. Of course, it didn't occur to Cave that he might be this annoying—clearly this was just some multiverse defect. Cave heaved his hips forward, his cock pressing against the other man's grinning lips. "Suck."

He did. He didn't take Cave in completely this time, but the man's actions were fervent, suckling short and hard. His tongue slid along the shaft, twirling a few times in a way that made Cave dizzy—especially when it flicked over the tip. The nuances were mostly lost, though, in each pulsing constriction, each sending a new stream of pleasure up Cave's spine. This man wasn't delicate, but he was good.

When a masculine hand reached up to his balls, Cave jerked with surprise—but not displeasure. No one had ever taken the care to touch him there before, but when he was alone…well, he'd taken a tug or two. It was almost magical how well the man touched him, grasping him firmly but not too hard, rubbing circles with his thumb into the sensitive skin and drawing a moan from Cave's throat. This man knew all the sweet spots, rolling his palms against Cave in a way that he'd always craved, though he'd never been able to communicate that to anyone else. Cave whimpered as cool air hit his cock, signifying the absence of his double's mouth—but the noise was quite interrupted as he felt the command of lips engulfing one of his balls. Christ…

Almost undone by the tug of his double's greedy mouth, Cave let one hand tangle in golden hair. He was starting to relax into sensation, even as pleasure coiled in his belly, slowly tensing to what he knew would be an incredible climax. As he felt a hand grasp his cock, he realized he'd let his eyes fall shut. He opened them, looking down at his alternate, and was startled to see brown eyes looking straight back at him.

His double looked so smug—but damn, he was a looker.

With no apparent sense of rhythm, the alternate spread his attention along Cave's groin, returning from sac to cock to sac over and over. The stimulation was so much harder, so much stronger than what Cave was used to; he hadn't realized until this moment how much he'd hungered for it. Yet still, he wanted more. He was growing weak in comparison to this man. He needed power. Cave groaned, whined, mewled into his double's motions, until at last he simply grabbed the man's head with both of his hands, forcing it along the length of the shaft over and over again, fucking his throat.

The man didn't resist, merely grasping Cave's legs for support as the prime CEO took charge. Cave didn't hold back. He relished the control, delighted in the gurgling noises from his alternate's mouth, loved being on top. He wanted this forever—but already he had built himself up too far. His peak was coming fast and strong, and he wasn't about to stop it. As he felt himself tipping over the edge, he ripped his double's head away from his cock, leaving the man's face open and ready for his climax. Pleasure engulfed his senses, a cry bursting from his throat as his cock spilled thick cum across his alternate's face and chest.

The seconds that passed felt like an eternity, like Cave had ascended to another dimension from the experience of having his every unspoken need catered to. However he felt about his clone, he had to admit that there was nothing like the touch of someone who knew him as intimately as he knew himself. He was suspended in decadence, gliding back to the moment only in an afterthought.

Cave's legs wobbled. As his climax ebbed into afterglow, he found his way to the chair, collapsing on it. Standing was going to be difficult for the next few minutes. His alternate smirked at him, cocky mirth agleam in his eyes, cum streaked over his face. On any other man, Cave would have hated the arrogance, but it just suited him so well—likely because he was, of course, him. The man was young, bright, and ready for the future—and he was damn attractive to a narcissist like Cave. His glistening face helped, too.

Long, dark hair entered his vision; Caroline had rushed out of the observation chamber, a towel in her grasp. "Sir?" She looked ready to hand the material to the stranger, but Cave held his hand up to stop her. He wasn't quite ready for his double to clean himself up.

"That, uh…that was…something," Cave muttered. He didn't think to ask Caroline if it had been as fun to watch as it had been to experience, too caught up—as always—in himself. He didn't even notice the shine in Caroline's eyes.

"Yes, sir," she purred, eyeing Cave's alternate. The younger man gave her a charming grin, and Cave once again found himself feeling possessive.

"That's my assistant. Get your own."

The man didn't flinch, instead licking his lips. Cave felt his cock twitch as the pink tongue found a trail of cum, drawing it into the clone's mouth. "I've got my own," his alternate said simply. The dreamy glaze that cast over his eyes was a familiar one; Cave knew what it was like to get caught up in the thought of a Caroline. "But you know, that gives me an idea…"

It was a stupendous idea.