Author note: Started as a drabble about why Irken's have sharp teeth... somehow became smut... enjoy~

Disclaimer: I don't own Invader Zim or any characters...

Warning: BoyxBoy... BoyxAlien? No like, no read... you've been warned...


Zim hummed, pressing himself closer to the teen, enjoying the feel of Dib's warm hands on his bare skin. He let his own hands slide across bare human shoulders, tangling in dark hair and pulling Dib's face down so he could kiss him. The human kissed back almost immediately and Zim smiled against the other's mouth. In seconds, the teen's tongue grazed his bottom lip and Zim complied with the silent plea, letting his tongue tangle with the others passionately. Dib's spit didn't burn him enough to hurt but his desire would have overshadowed the pain anyway.

Zim shifted in the teen's grasp, feeling their bodies rub together, sending sparks of pleasure through him. He let Dib lower him onto his back, letting his lekku flick upwards out of the way, glad the teen's bed was beneath them to cradle his Pak. Warm hands ghosted over his skin, toying with his pants and Zim groaned. He felt a tremor go through him, making him arch into the touch. The human grinned and Zim pulled back, nipping the teen's lip as punishment. He hadn't expected to draw blood with the action but he did and Zim whined as Dib pulled away in pain.

"What the?" Zim licked his lips, tasting Dib's blood on them... he felt a purr bubble up his throat at the foreign taste. Zim swallowed, eyes locking onto Dib's and finding the teen upset with him. "Why'd you bite me?" He asked and Zim blinked silently. He hadn't meant to... The human sighed at his silence and spoke again, curiosity in his gaze now. "You can't eat meat so why are your teeth so sharp anyway? Zim frowned, knowing Dib wouldn't resume their activities until his curiosity was sated.

"Irkens are carnivores and always have been. We love snacks but we can eat meat. It's the chemicals you humans fill your food with that makes me sick." He licked his lips once more, the taste of blood faint now. "Many Irkens love the taste of blood... of flesh. Some have been known to eat their enemies..." Amber eyes flickered with fear, warm hands gripping his hips tightly and Zim blinked confused by Dib's reaction.

"You won't eat me will you?" Zim chuckled, pulling himself close and licking the remaining blood from Dib's lip, the injury too small to bleed alot. He closed his eyes, feeling the teen tense in his grasp. Dib shivering half in fear at the possibility of being eaten and half in pleasure at having Zim so close to him. Zim had to admit he liked the taste of Dib's blood but the thought of eating the human had never crossed his mind. He pulled back a little, smiling kindly, hoping to placate the teen's fears.

"No." The human sighed in relief and Zim waited for Dib to resume their 'activities'. The teen's curiosity was frustrating sometimes. Warm hands loosened their grasp and Zim sighed happily as Dib kissed his cheek, groaning as butterfly kisses were trailed down his jaw and to his neck. Once there, Dib set to work on creating a hickey and Zim let him, knowing the human needed a moment to get back into the mood. Zim didn't bother to hold back the noises the teen drew from him, knowing Dib liked it when he was loud, especially when they were alone. The teen pulled away, amber eyes dark with lust again.

"Zim~" He groaned in response, burying his face into Dib's neck as those warm hands moved, slipping beneath his waistband and pressing against his heated flesh. Zim jolted, muffling his moan in Dib's neck, feeling the human chuckle at him. "Zim, I love you~" Zim shivered, entire focus on Dib's touch and not his words. He wasn't gong to wait anymore.

"Diiiibb..." He whined, tugging him down for a bruising kiss. Both were panting when he pulled away. "Hurry." Zim didn't have to tell him twice, the teen already tugging the rest of their clothes free and discarding them quickly. He watched as the human coated his fingers in lube. Desire filled eyes met his, waiting for something and Zim tightened his grip in Dib's hair. "I love you too..." He whispered, feeling his squeedlyspooch twist at the loving look he received. A gentle kiss cut him off, Dib's attempt at distracting him from the feeling of being stretched as slick fingers entered him. Zim forced himself to relax, knowing it'd help like it had the last time they'd done this. Dib worked slowly, letting Zim adjust properly and distracting him with more kisses.

It didn't take long for the pain to subside and for Zim to want more than the teen's fingers. He growled, puling away from the kisses to meet Dib's eyes. The fingers retreated without the need for words yet Zim still found himself whining at the loss despite knowing something better was to come. The human didn't even smirk, too focused on his task. Zim let Dib reposition him, feeling the human press against him. He shuddered, mewling as Dib entered him. The human stilled once inside, waiting for him to be ready. Zim took a deep breath, shifting until comfortable. He wrapped his legs around the teen's waist.

"Zim?"

"Move." The effect was instant, the human setting a quick pace, knowing where to aim from the other times. Zim could only groan, rocking himself to meet the teen's movements, dragging his claws lightly across the other's pale back. Dib kissed him, smothering sounds Zim didn't realise he was making. It didn't take long for them to finish, cries muffled by the other. Dib fell to his side and Zim let him drag him into a hug. He didn't care that he was sticky and the air was cold, still hazy from before. He felt Dib press a chaste kiss to his forehead, then his cheek before kissing his lips. Zim kissed back, feeling tired and loved.

"We'd best get dressed, Gaz will be home soon." Zim groaned, forcing himself up on tired arms, looking down at how messy he'd become. "Wipes are in the top drawer." Zim nodded, letting Dib kiss him once more before watching him leave the room to shower. He cleaned himself and pulled on his pants in silence, sitting on the bed afterwards and waiting for Dib to return. A few minutes passed and Zim looked up as Dib entered again, the teen smiling lazily at him. He waited as Dib pulled on some boxers and a pair of pyjama pants. The human yawned and Zim climbed into the bed, watching Dib join him, warm arms pulling him flush against his body. Zim nuzzled his human's neck and letting the steady beat of Dib's heart lull him into stasis.