"Zim, why?!"

nsfw ;)

Zim moved slightly, his hand left on Dibs inner thigh. "Why'd you stop?..." The alien spoke, groggily, taking Dib by surprise.  "Oh you're awake.."

"Us superior beings don't require sleep, now if you'd please, continue." 

Dib rolled his eyes, even when he was at his worst Zim was still narcissistic as fuck, but thats what he liked about Zim. He wasn't afraid to be himself, aside from the whole disguising his alien-ness in public. Dibs fingers caressed the irkens antennae, watching him squirm below. Zims soft feminine moans made Dib hard, his boner poking against Zim. "Wh-What the hell is this?!" Zim exclaimed, his small hand grasping Dibs hard-on through his tight pants, causing Dib to moan out, biting his lip.

"Fuuck Zim! That's my dick!" 

Zims face was nearly priceless, and if Dib hadn't been so turned on, perhaps he would've chuckled a bit. Zim thought for a moment, reflecting on the "educational adult videos" he watched to gain some insight on the humans and their greasy wants. "Oh~ So you... desire me?" Zim said, his voice smooth and a tad cocky. Dib nearly choked on his breath, "Y-yes space boy... I do..." 

"Then prove it."

Dib blushed, he expected Zim to be demanding, but he didn't want to be the submissive one. Taking control, Dib continued to play with his aliens antennae, while kissing the side of Zims neck, which was cold and less smooth than human skin. The humans hand traveled down by Zim's thigh, caressing it softly before working his fingers towards the aliens crotch. Dib hadn't even thought of the possibility of Zims genetalia being different, but when his hand reached his crotch he felt it was slightly wet, and there was an absence of cock. Was Zim a girl? Did Irkens have genders? 

Zim must have noticed the confusion on his face, teasing him "Whats the matter stink-boy? Never felt the Irken's double pleasure before? Thats why we are the better species~" 

Double pleasure?? Did this mean...? Dib felt something in Zims pants harden. By god, Zim had a penis and a vagina! It was Dibs dream come true !! The Irkens pants slid off, and the human tried to stroke the slimy member between Zims legs. It wasn't like a human dick, which was to be expected, it curled around Dibs fingers. This needed some getting used to. 

As Dib stroked it, Zim gradually became much more submissive, and he was practically purring, his antennae vibrating around Dibs finger. "F-fuck me..." He moaned and pleaded, and Dib could feel that Zim's vagina was also wet, he was very turned on as well.