As the airlock's automated scan triggered, Lilith punched in a code in the control panel. The automated voice barely had time to blare "Unknown Xeno-organisms Detected" before being overridden. My gaze shifted from Lilith to the backpack she carried, where three tiny human-like creatures were clinging from the top and observing wide-eyed. I could hardly blame them for their surprise: we were probably the first extraterrestrials their civilization had encountered. Hell, from our perspective, they were only the second race we'd been able to communicate with at all, after the slime-people of Mjonakk. And these little cherubs from the world they called Valath were a hell of a lot cuter.
 
The door to the airlock opened, and we stepped through to the cool, poshly-decorated main hallway of the Magellan's Venture (our ship). Lilith immediately unsealed the front seam of her excursion suit, revealing a V of silky skin and a slightly criminal view of her cleavage. Not that I wasn't used to her sporting this look, but I felt a little uncomfortable with visitors aboard. "Did you want me to introduce them to the ship while you change?" I offered.
 
"Actually, I'm OK like this. Although I suppose I could stand to freshen up. Alright then." She leaned over, carefully lifting the pack off her shoulder and handing it my way. She pressed the translate button on her collar, and spoke again to the little people hanging out of the pack. "Celty will show you the bridge while I freshen up. I'll be back again soon!" The speaker built into the excursion suit repeated her message in the Valathian language, and I took the handoff of the pack. Lilith waved a characteristically flirty goodbye and took off one way down the corridor, while I gingerly hoisted the pack over one shoulder and carried our visitors to the bridge.
 
The Valathians were suitably impressed with the Bridge, with all its multiple stations and wall-spanning holodisplays. I set them on a spare seat and began showing them what the SCC (Shipboard Computing Core) was capable of. I decided to record a daily log. "Day six of the sojourn to Valath. Our cultural exchange continues to progress. Mechanical language understanding has crossed 80%, and Lilith and I are beginning to be able to speak and understand some phrases directly. The parallel evolution between their species (as yet unclassified) and homo sapiens continues to amaze. The Valathians were interested in the ship, so we judged it safe to bring a small envoy aboard. Allow me to introduce Nak" (a muscular blond male), "Urj" (a busty female with striking violet hair), "and Lin." (a slightly younger female with black hair). The three waved at the screen, where their recorded reflections waved back.
 
After a short while longer, Lilith returned, still wearing her partly-open excursion suit. If anything, the seal had slipped open even lower, revealing some midriff and allowing her round assets to ply the top farther apart. "Hey there tomboy," she greeted me, "wanna trade off and freshen up, yourself, while I show our guests around the Science Bay?"
 
Trying to hide my blush, I accepted the offer and headed off. I just hoped none of the Valathians picked up on the nickname: Lilith was the only one who could get away with calling me tomboy. Well, I heard it a lot because we were the only two on this mission, but it still got me every time. I took my time changing out of the constrictive excursion suit and getting a rinse off before putting on some a simple fitted shirt and shorts. I brushed my short hair across my forehead with one hand, and headed out to the science bay.
 
The Bay was dark when I'd gotten there; apparently Lilith'd finished showing the Valathians around already. I invoked the computer assistant. "Computer: Lilith's location." The reply came back immediately: Personal Chamber 1. Her room. I turned back the way I had come.
 
For privacy, our personal chambers weren't immediately next to one another, but close enough. I walked up to the door and put my hand on the plate. With a pop-hiss, the door slid open. Then I made a face.
 
Lilith was sprawled on her bed, dripping with sweat. Her excursion suit was crumpled on the ground next to the bed, one hand massaging the sweet spot between her legs. The Valathians were nowhere to be seen.
 
"What the fuck, Lilith! Where are they?"
 
She just looked up at me and smiled weakly, her hand pausing in its ministrations. My gaze followed hers down her toned abs to the glistening slit that quivered even as her hand left it. Realization dawned on me. "You didn't..."
 
She nodded. "All... three..." she moaned faintly. "It's... so nice... they're... moving..."
 
I was beyond taken aback. What had happened to protocol? To safety precautions? To common fucking sense? We were supposed to be on a peaceful mission, not sexcapades in space! The dangers of... well, I couldn't even imagine. And yet, right in front of me Lilith was squirming and squealing in pleasure with three alien diplomats occupying her sex organ.
 
While I stood dumbfounded, Lilith's satisfaction seemed to reach a peak, and she flopped back, her muscles spasming. She relaxed, taking deep breaths, and a little dribble escaped her slit... followed by one... two... just two unclothed cherubic aliens.
 
It was the older two, Nak and Urj. Lin, the smaller, black-haired one, was nowhere to be seen. I broke my stupor and fully entered the room, approaching the bed where the sopping wet cherubs were chattering to one another animatedly amidst Lilith's thighs. Desperately, I switched on my translator to try and apologize.
 
"Truly spectacular!" said Urj, the blonde whose voluptuous figure would've been nigh-impossible at human size.
 
"I cannot believe our species has been missing out on something so amazing," mused the male, Nak.
 
"You... enjoyed it?" I mumbled, bewildered, into the translator.
 
"It was unbelievable! We are truly lucky to experience such a thing before the rest of our species," Nak told me.
 
"Did you know?" Lilith added as she caught her breath, "The cherub species lacks sex organs. The whole concept of intercourse was novel to them." I couldn't help but look and see for myself, that indeed, she told the truth. Neither Tak nor Urj had anything but a smooth fold of skin where a penis or vagina should be. I was somewhat amazed that it had taken us so long to find out.
 
"And fascinating! The concept of males and females connecting this way to reproduce is very intriguing," Nak continued. "For us, reproduction is quite a bit less... personal. I shall have to explain it in greater detail later, when I am not so... messy."
 
"You tease!" said Urj. "Still, their system is a fascinating complement to ours. In any case, we have much to report."
 
"B... but what about Lin? Wasn't she... in... there, too?" I hesitated to stare closely at Lilith's still-swollen vagina, which showed no signs of relinquishing its third rider.
 
"Indeed. But Lin will be staying with Lilith."
 
I raised an eyebrow. "For how long?"
 
Lilith answered. "Indefinitely."
 
I wanted to protest, but it seemed -- like much of what had transpired -- that it had been decided without me. "I-- I had better be going," I said finally, giving up. I half hoped that I would wake up the next day and discover I had dreamed this whole affair. Of course, that was useless.
 
As I departed the chambers, I heard Urj continuing to speak animatedly with Lilith, and wished I hadn't. "Say, does Celty also have a sex tunnel like yours? Is there anyone with the alternate organ in your crew? I'd be fascinated to see it."
 
"Unfortunately, it's just us," Lilith explained. "Two of a kind..."
 
I let the door shut behind me and ran.
 
* * *
 
Almost a whole day later, Lilith entered my quarters where I had shut myself away. I was moping, the cover to my bed pulled up almost over my head. "How goes your interplanetary sex romp?" I asked halfheartedly.
 
"Better than I could have imagined!" she replied with a bit too much verve. "The cherubs are fantastic in bed!"
 
"Does the populace know you're stuffing their ambassadors into your 'sex tunnel' like a horny teenager?"
 
"Actually, most of the populace was rather jealous to hear it. I spent the past day on the Valath surface convincing them that nobody need be left out."
 
"... and how many pervy aliens did you stick inside your cooch now?" I mumbled.
 
"Fifty-three!" Lilith announced proudly.
 
THAT got me to sit up. "Wait, WHAT?!"
 
"If that shocks you, wait until you hear how cherub reproduction works."
 
"Oh god..." I dove back under my pillow. "I have such a bad feeling about this..."
 
"It's really crazy. You remember how they have no sex organs? Well, it's because their WHOLE BODIES are sex organs."
 
"You mean you're using them like sex organs..."
 
"No, I mean their entire body is used for reproduction." As she lapsed into her lecturing voice, Lilith ran her fingers up my spine, teasing at my sleep suit. "You see, when two cherubs love each other very much, or just get really, really comfortable together, they explode."
 
"They... what?" I let her lift the pillow off my head, but I still wasn't moving. If anything, I was more still than before.
 
"Explode. Into a puddle of reproductive cells. Every cell in their bodies divvies up its chromosomes and splits into what I guess are their equivalents of egg and sperm... a giant puddle of cherub gametes mixes together and becomes a kind of living zygote slime. Eventually it grows into several, maybe dozens of little baby cherubs, each the offspring of the two that died to form it. Isn't it beautiful?"
 
"I'm shocked that evolution somehow found a method of reproduction that's objectively more gross than sex."
 
She slapped my back playfully. "Oh, you fuddy-duddy. It's fascinating! And here's where it gets sexy again. See, they're biologically programmed to seek out ideal places to mate like this. Someplace moist, warm, and dark so predators don't find the zygote slime before the baby cherubs are mobile." Lilith's hand played its way down my back, stroking my ass and inner thigh, punctuating her explanation with a finger on my... well, you know.
 
I rolled over, facing her while my sleep suit spilled open across the chest, showing my less than impressive assets. Lilith leaned forward, pressing her considerably more impressive assets into docking position. Her lips splayed across my ears as she whispered, "In my pussy, fifty two cherubs achieved such bliss that they became puddles of cum."
 
"...but earlier you said fifty-three..." I found it difficult to continue the conversation as her hand expertly slipped off my remaining clothes, and began doing expert work on my slit. As it had many times during our uneventful journey before.
 
"That's right... one of them managed to hold herself together, worrying about you." As I arched my back upwards, Lilith positioned her own pussy up against my moistened opening. Since when had she undressed? Or had she even been wearing anything to begin with? Such thoughts vanished when I felt something... entirely unfamiliar.
 
"That's right, Lin... Show Celty how you-- oohhh! -- feel!" As she thrust forward, the sensation grew stronger. It was a tiny bulge, passing straight from between Lilith's nether lips into mine. No, not just a bulge. It was alive, moving, squirming. I suddenly realized I was feeling tiny little hands massaging all over my opening. Lin, the younger cherub! I --
 
ohhhhhh... couldn't help but writhe in pleasure. Lilith was pressing herself directly up to me, but she still found it in her to massage my chest. Meanwhile, the tiny humanoid was being pushed out of Lilith's vagina, and bit by bit, my vagina accepted her presence ever deeper, her miniscule hands massaging a path into me. I could only grab at the sheets with all the strength I had...
 
Soon I could feel Lin's tiny shoulders pressing at the narrowest ring of my vagina. They squeezed, while my outer lips squeezed and pulsed around her thighs. Lilith sighed and relaxed, having passed the tiny girl out of her body and probably come in the process. But for me the peak was yet to come...
 
A cry in an unfamiliar voice echoed through my head, and by the time I realized that it was Lin's, echoing through the inside of my own body, she had passed the narrow point of my vagina up to her hips. My vulva lapped at the final traces of her feet while her hands plied every crevice of my insides, filling me with heavenly sensations beyond anything I'd ever experienced. With the cherub's body fully engulfed in mine, finally I got a pause for breath. I lay on my back, Lilith snuggled up on one side amusedly watching me exhale raggedly. I felt strangely at peace.
 
Then Lin's wriggling resumed in earnest, and I could hold back no longer. I pinched my eyes shut and arched my back as I came. I felt my lower muscles squeeze Lin's tiny body tight, and I savored the feeling of fullness. As my peak subsided, I felt Lin sink out, gradually getting expelled from my opening.
 
I opened my eyes and looked down between my legs, where the lithe form of a cherub was asserting itself, sitting up. "But I thought they--" I said to Lilith, confused and wondering if I'd been tricked. She just shook her head.
 
Adorable little Lin stood, brushing the sleek black hair out of her eyes, sopping wet in my love juices but with a triumphant look on her face. She looked me in the eye and spoke: "I'm not done with you yet."
 
Her grin was magical.