Work Text:
“Is normal for Eridians, Grace.”
Rocky was standing, waiting for an answer that Grace wasn’t sure he could give. The glass dome stood between them like glass at an aquarium. It made Rocky look like some sort of animal at times, despite his intelligence, which often surpassed his own.
“It’s not really normal for humans,” Grace said back carefully. His legs were kicked out in front of him as he snacked on some protein bars.
“Humans only have one mate, forever, question?” Rocky asked back. “On Erid, many mates. Adrian is Rocky’s first mate. Rocky have many others.”
Grace thought about it for a moment. “I guess humans have many mates, too, sometimes. There’s no rule against it. People usually just have one at a time.”
“Grace have no mate at all. Very sad.”
“It’s not the end of the world,” he replied, waving his hand dismissively. “Mates can be overrated.”
“How Grace make new human, question? New small human, question? Not need a mate, question?”
Was he asking how humans reproduced? He really didn’t want to give a sex ed lesson to an alien, but he’d be lying if he said he hadn’t been curious about the Eridian’s mating rituals.
“No, if you want to make a new human, you need a mate for that. It takes two to tango.”
“Rocky not know what means.”
“Tango is a type of dance,” Grace explained, taking a bite of his food.
“Rocky and Grace dance already. Rocky and Grace are mates, question?”
“What?” Grace stood up quickly, almost choking on his food. “No, no, no, Rocky and Grace are not mates. We are just friends.”
“How humans mate, question? How, question?”
“Uh, are you sure you want to know?”
“Yes! Is for science!”
Grace sighed. He had to admit, he understood the curiosity. Despite not wanting to go into detail about the process, using vague euphemisms wasn’t going to advance their understanding of each other.
“To reproduce, a human needs to find a counterpart. I have body parts that fit with some other human’s body parts. If we put those parts together, I release a… fluid that goes into the other human, and it grows a new human in their abdomen. Eventually, the new human comes out.”
“Similar to Eridian,” Rocky nodded. “Adrian give Rocky fluid and Rocky make new Eridian.”
Grace’s eyes widened. “You’re a girl?”
“Don’t understand.”
Okay. It makes sense to assume that not every life form would distinguish between sexes. Even humans were beginning to move away from that with time.
“You’re the one who makes new Eridians? Small Eridians come out of your body?”
“Yes, but next time will be Adrian’s turn. Rocky give fluid.”
Oh, so they could switch roles. They took turns giving and receiving. It made sense, he supposed.
“Does it feel good?”
He wasn’t sure why he asked. Maybe out of some morbid curiosity, or it was just some random urge, but the minute the words left his mouth, he wanted to claw them back.
“It feel very good. Humans feel good too, question?”
Grace felt himself flush. “Yeah. It feels good for us, too.”
“Rocky want to see body part where fluid come out.”
“Whoa! No, Rocky, that’s not something I can do.” He instinctively covered his crotch with his hands.
“Only for mate to see, question?”
“Yes, exactly. It’s not something humans show to other humans unless they are going to mate.”
“Understand.”
He sighed in relief until Rocky spoke up again.
“But sometimes Rocky hear Grace fluid come out. When Grace goes to other room. That is body part, question?”
Does Rocky think he’s jerking off every time he goes to take a piss?
“No. I mean, I guess. It’s the same body part, but I’m releasing a different fluid.”
“Amaze!”
So, because of Rocky’s horrendously bad boundaries and sharp echolocation, he’s already seen his cock. Nothing gets past this alien.
“Rocky want to mate with Grace.”
Grace almost choked on the air. “What?”
“Rocky like Grace. Like Grace so much. Would be fun to learn humans mating. Grace learn Eridian mating, too.”
“No, I… don’t think my parts would fit with your parts.”
“Oh. Is sad but understand. Rocky can show you Eridian mating parts.”
Grace had to assume that mating on Erid wasn’t as big a deal as it was on Earth. Maybe it wasn’t taboo at all. Just another bodily process that they had to do. One that felt good, but was ultimately just a necessary part of life.
“Uh… okay.”
Rocky flipped onto his side and presented the lower half of himself to Grace. “Is for food and mating.”
So the Eridians’ mouths were also their genitalia. Not really that different from humans, Grace joked to himself.
“And if Rocky touches here, feels good,” he added.
“Okay, I don’t need a demonstration.”
“But Rocky see Grace body part release fluid. Rocky show Grace.”
Rocky began to shudder as he rubbed at the entrance. There were some high-pitched tones that emitted as he moved his arm around the hole.
And Grace couldn’t look away.
It wasn’t every day that a human got to see an alien jerk off, and Rocky was truly alien to anything he’d ever seen before. The way his legs kicked out in pleasure was all too human, though. And the way he made those little whining noises as he neared his orgasm.
“Oh my god,” Grace whispered, as he watched Rocky’s hole begin to pulse. A bit of black fluid began to leak from it.
“Rocky… show Grace,” he said, his breathing coming a bit heavy. “Grace understand.”
It was an insane thing to admit, but it was possibly the sexiest thing he’d ever seen in his life. What kind of evolutionary instinct had primed him to find an alien’s orgasm to be as hot as he did? There was no reason for it.
Maybe it was the exhibitionism. Seeing something take pleasure in an orgasm without having any shame along with it. Wanting to show itself off to another species. Wanting to share something intimate and vulnerable, just because he could.
“That was… wow.”
“Like, question?”
“Yeah,” he said, flushing a bit more. “I liked.”
“Maybe Grace show Rocky human mating ritual one day.”
Grace felt the strain of his cock against his pants.
“I can… I can show you now.”
“Yes! Yes, now!”
Was he really going to do this? Was he going to embarrass himself by jerking off to an alien?
Rocky waited for him expectantly.
“I’m shy,” he warned.
“Not understand.”
“Of course you wouldn’t,” he mumbled as he worked the zipper.
He managed to undo it, and he stood in front of Rocky with his cock in his hand.
He was already hard. It had been a while since he’d last jerked off. With his new roommate moving in, he had tried to be decent by not sneaking a quick session in. But Rocky was here, practically begging to see this.
He began to stroke himself. A moan escaped his lips at the feeling.
His mind flashed back to Rocky, rubbing his hole. The way his body twitched, convulsed. The way he lay there, almost submissively on the floor in that display of pleasure.
Grace leaned his hand on the glass, letting Rocky get up close.
It would be easy to just say that this was all for the sake of scientific understanding between two species. That Grace was just doing his part in furthering Earth-Erid relations. But this wasn’t about that anymore. Maybe it was at the start, but a line had been crossed, and now it was something else.
He found himself getting closer to the edge.
“Rocky like Grace feel good,” he encouraged the human.
And that was enough to send him over.
He came in hot, white spurts that hit the glass hard, right where Rocky was standing, like it was some kind of space condom.
Grace shuddered. “Sorry about the mess.”
“Grace very pretty. Not be sorry.”
He huffed out a breathy laugh and sat back on the floor. “You know what? Rocky very pretty too.”