Dib was bound and gagged because he tended to get disobedient, strung up, standing with his arms tied above him. That was alright. It was all part of the power-play.
Zim walked around him, face carefully expressionless.
The human was grown and muscled, scarred from long forgotten battles. Dark strands of hair dusted him, arms, legs, stomach, leading into his straining pants. The alien ran a gloved hand over his prisoner's chest. Could feel the overwhelming warmth, even through the rubber. A heart beat overtime against his palm.
He slid down a shuddering shoulder, until he reached the strange little nubs. 'Nipples' Dib had called them. And they were sensitive. Even barely ghosting across them, they reacted. Dib reacted. His muscles contracted, goosebumps spread across pale skin. Pale,frail skin. Zim paid special attention to Dib's the weird nubs, rubbing,caressing,twisting until they were pert and Dib was obviously affected. He panted though his nose, wet saliva in his mouth.
The irken found the power he had over the human, heady. That was why they did this. Well, and Dib liked it too, if the ever growing bulge in his pants was any indication.
"Mmph-." The human tried to speak beyond his gag. Zim ignored him for a minute, leaning forward and letting his tongue flick over the tip of a nipple, feeling the shiver work its way through his mate's form. He did this several times, bringing his teeth into it a bit. Dragging them over the sensitive peaks, relishing in every soft sound and movement he wrought.
"Zimph." Dib half moaned, against the metal in his mouth.
The irken finally went to his face, caressing his cheeks. "What is it?" More stupid muffled sounds. "If I un-gag you, will you be good?"
A dark brow raised in response. 'Unlikely' Dib's eyes said. He nodded anyway. Zim knew to remove the gag was to invite all kinds of trouble. But, the thought was exciting, so he carefully unhooked it and let it fall to the ground, in range, just in case.
Dib licked his lips, swallowed. "Stop messing around." The human commanded, fists clenching in his bonds. "Touch me, fuck me." His voice was loud but, gruff in the darkened room.
Zim glowered, reaching up and grabbing a nice handful of dark hair and yanking it until the human's head tilted with the force of it, blunt teeth hissing with pain.
"You're not really in a great position to be giving orders, fool."
Dib smirked, eyes half lidded. "Fool, huh? Why don't you learn some new insults, Zim?"
Another harsh tug on his hair and his eyes slid fully shut, disobedient mouth falling open in some sick mix of pleasure and pain. Zim leaned forward and licked a steady path up his neck, teeth scraping. He stopped occasionally and sucked, bit a dark bruise into existence. Without the gag, Dib's naturally vocal mouth let loose all kinds of curses, moans, hisses. The human's hips rocked forward, wanton and eager.
Zim grinned against the marks he had made. "You want me so badly." He stepped back a bit. Dib made a breathless noise of shock as the cool air hit him, where their bodies had been flush, where alien saliva was. "You're a filthy xenophile. I know what I do to you." Zim watched the human's eyes, as they danced across his body, examining him. "You like my antenna, my eyes." Big and bug like, glowing an unearthly pink color in the dark. "You like my body. How it's different than yours." So angular and full, wide hips, alien bone structure, the strange genitals between his legs, three fingers on each hand, three toes on each foot. "You like when my strange tongue shoves its way down your throat." Ridged and too long, too thin and it invaded his entire mouth.
Zim gleefully saw Dib's eyes darken, his own tongue lick his lips.
"Disgusting." Zim whispered, but his voice held no malice. Because he liked Dib's alien body too. Liked that they obviously were not made to fit together and yet they did. He hummed and inched forward again, hands going to the human's pants, unbuttoning and unzipping, pulling them down. Dib was already hard, cock pressing up against his belly, moist at the head, pink and swollen.
The irken grinned. Overwhelming evidence to support his theory. He ghosted over the human's length, hearing the sharp intakes of breath. The tiny whimpers.
"S-stop. Ju-ust touch me." Dib whined, arms struggling in their bonds. The irken walked forward until their bodies were flush again, until he could feel Dib's dick against his stomach, trapped between them. He swore he could feel it pulse.
"No. Not until you say please, you slut." The word slipped from his lips. It was harsher than anything he'd said before and he waited to see the human's reaction, making sure it was okay. Dib's cock pulsed hard against Zim's body again. The alien could see his pupils as they contracted and blew, darkened irises. A light flush on his face, darkening. Oh, he liked it.
Zim stood on his toes until he could press their lips together. He tried to keep it chaste, an acknowledgement, a reward. He failed because kissing Dib was the best thing he'd ever experienced in his long life. It was above blowing stuff up, destroying, burning things, flying as fast as he could, the fame and glory. It was better than sweet snacks and oxygen. They could spend hours just kissing. And it took him out of his head, into a place that was just their tongues slipping,sliding,intertwining. That was just their teeth, soft lips, fast breathing.
Zim let his tongue slide past the human's back teeth, and down, down his throat. The first time he'd done it, Dib had jumped backwards, obviously weirded out and confused but, also he had that look. The same look he'd had when Zim had called him a slut. It turned him on. So, he hadn't done it again until one day Dib had hesitantly asked him to. Zim complied and it had spiraled from there. They learned what they liked, disliked. They experimented, they played their little roles, little games and it was pretty fucking awesome.
Zim reluctantly pulled away despite feeling the human's moans, literally on his tongue. His own face was flushed,breathing labored, he knew. So, to make up for it, he scowled and grabbed Dib's hair again. "So, what's it going to be, huh? Say please? Or I leave you here, strung up and wanting, until I feel like coming back?"
Zim wouldn't do that. He was already unsheathed, an uncomfortable wetness between his thighs.
Dib panted, lips swollen, well kissed. "F-fuck you."
Zim tugged hard on his hair again, until he heard a tiny whimper escape that terrible mouth. "Now, you'll need to say please and call me..." He hesitated, thinking of what he would make the human call him. Something properly noble and also humiliating for Dib.
"My Tallest?" Dib suggested, smirking devilishly. He knew it would get him in trouble. He knew it would have a deep affect on the irken.
"No!" Zim snarled, fisting the dark strands of hair. His other hand went to the human's dick again, grabbing it, not too hard, but not exactly gentle either. "Do not call me that,again." Dib gasped, body torn between pushing closer and pulling away. "No, you will call me 'my lord'." Might as well.
Dib huffed, hips twitching, arms straining. "F-fine. Just...please."
Zim loosened his grip, but still kept firm, sliding up the human's length, once, twice. Saw his throat work, saw the tiny drop of pre-cum as it slid from him.
"Please? Please what, you filthy slut?"
Dib groaned, desperate, he unsteadily jerked into Zim's hand, who immediately let go. The human cried out, bereft. Even his legs were shaking.
"P-please, my lord, just touch me. Fuck me, please." Zim growled, pleased. And he grabbed the human's dick again, pumping him in earnest. Dib's relieved shout was music. He stroked him, played with him, until he knew the shaking, the faint cries meant his orgasm was near. Zim let go, rubber glove sticky. The human whimpered, as the alien wiped his hand on his naked chest.
"Stop your pathetic whimpering. Have patience." Zim stood up on his pak legs, so he was even with the human's bonds. It took him a second but, soon they were obsolete and Dib's arms fell to his side. He heard him hiss with pain, all the blood probably running back into them.
Back on his feet, Zim grabbed Dib's wrist (gently) and pulled him towards the bed pushed away in the corner. "Come."
The human followed without argument, flopping down onto its surface when pushed.
Dib felt hot and uncomfortable all over. He was painfully aroused. And he watched the irken as he pulled the necessities from his pak. Dib smirked a bit. Despite the irken's previous misgivings about lube and condoms, he seemed to have gotten over it and was even carting the stuff around himself.
Zim slicked up his gloved fingers. "Spread your legs, slut."
Dib's mouth fell open and his dick twitched. Despite the urge to argue, he really,really just wanted Zim. So he obeyed, opening his legs, leaving himself exposed. The human swallowed, nervous even though they had done this before, tons of times.
Zim kneeled on the bed, and after a cursory moment to make sure that Dib was genuinely okay (not afraid or unwilling), the alien let one finger slick up the human's entrance, before pressing inside. Slowly, slowly. He expected the human's tiny gasp. Expected the biting of his bottom lip as he worked him open, slipping in and out, in and out for several minutes before adding a second finger. In and out. He spread them, scissoring. In and out. Tight muscles clenched around the intruders. Hot and slick.
This part wasn't Zim's favorite. But, he deeply enjoyed watching Dib go from nervous to a wreck. He was back against the bed, head thrown back, chest heaving. He liked seeing his throat work with the effort not to make a lot of noise. Zim slid his thumb into the mix and granted, his hand was pretty tiny (it was easily dwarfed by Dib's) but, apparently it did okay with stretching out his human.
Dib was always enchanting like this, no longer really thinking, trying to be in control. But, a slave to whatever was happening. Watching him was enough to have the alien remembering his own genitals, his 'alien dick and pussy' as Dib had so eloquently put it awhile ago. He was fully unsheathed, and sticky. Zim pulled out of the human and stood to take off his pants, leaving his tunic and gloves.
"F-fuck, Zim." Dib whined and it sounded like a plea. The irken hmmed as he got back on the bed, scooting closer between his mate's thighs.
"That's not what you are to call me." The human panted, dark brown eyes (so brown they were nearly black with desire) scanning the alien's half naked form. He took in how the tunic barely covered his alien desire, how his thick thighs were obviously slick with pink precum. Dib whined again, head falling back against the bed.
"P-please, my lord, fuck me." He pleaded, breathlessly.
Zim didn't need to ask how the human wanted to be taken. It would be fast, hard. He grabbed Dib's hips, scooting closer until he was pressed up against his mate's eager opening.
"Mmm. Since you asked so nicely."
Then he shoved inside. Dib's high moaning keen was music to his antenna. Zim didn't give him a chance to recover before he pulled most of the way out and then back in again. Over and over, so fast that their thighs slapped together, that the bed moved with their movements. So fast that it did what Dib desired in these moments. It took him apart, tore him into pieces, overwhelmed him until his mind had to stop thinking. It was just pure, simple, white and black. Nothing but pleasure, the sensations that washed over him. Zim inside of him, filling him, emptying him. The fabric of the sheets under his hands, irken skin under his nails. And he didn't know what he was saying, what words and sounds spilled from him because he didn't think, couldn't think.
But, Zim could. And he could hear all the 'please's, all the 'yes's, the 'oh god's, the 'fuck's, the 'my lord's, the 'Zim's. It was purely from experience that he was able to get Dib's 'prostate'. The humans had such stupid words for things. Just every now and then he could hit it just right and it would send his mate into another frenzy of babbling, clawing at whatever he could reach. Dib was such a pathetic mess. He wanted their bodies to become one so badly.
Zim craved it all for his own, craved Dib, loved Dib, fucked him into the mattress until he was this pathetic mess. He hissed and clicked little alien noises of encouragement at his mate. He felt his own orgasm approaching, curling tight around his middle.
So he pushed the human's legs up, moving closer. "Touch yourself." Zim commanded,voice hoarse with the strain.
Dib obeyed, unthinkingly, reaching between them to his dick and pumping himself, probably way too hard, too fast. Zim growled at the sight, as it sent a spear of hot desire though him and it was enough to send him spiraling over the edge. He shouted the human's name, the only thing he could think of and spilled himself inside Dib for a full minute, white hot, sticky and pink.
Between the time Zim's orgasm began and ended, the human reached his. He shot himself between their bodies, shivering as he felt the alien's cum pool inside of him. Dib went limp and waited a few second before Zim did the same, collapsing on top of him. Their limbs were weak and slicked with sweat. They laid together for a minute or so, just letting heart beats return to normal, breathing to even out.
Zim was the first to speak, voice quiet, concerned. "You are...okay?"
Dib felt his own lips curled into a satisfied smile. Zim was making some kind of buggy noise deep in his throat that was there even when he spoke. It was like purring, but much more clicky. He gathered the energy to raise a arm and wrap it around the irken.
"Yeah. 'm fine." Another moment of silence with the exception of weird alien sounds that he let himself savor. It couldn't last long with them, however.
"Slut',huh? That's a new one." He felt the alien stir a bit. "Where'd you learn that from?"
Zim grumbled, burying his face into Dib's shoulder. "Shut liked it."
Dib chuckled and knew he'd be sore later. "You googled 'dirty talk', didn't you?"
Instead of replying, Zim just lazily flopped a hand against Dib's mouth.