"The Ear Thing" meant Xiv ear fucking into her living brain. 

On one particularly long previous run, Xiv had taken a break from tweaking the ship to really dig into studying humanoid anatomy. They found the whole idea of differentiated tissues and organs and systems working together fascinating and cool, much like a ship, with all the intricate parts and complexities and challenges. Xiv's own body was all homogenous and organized on a different scale on the fly (as they had repeatedly tried to explain to Ily, who only sort of understood it). All of Xiv could sense and resonate (or speak) and breathe as well as any other, and could firm or contract or stretch as needed. It was one of the many ways Ily found her partner amazing, but that went both ways. The two of them loved each other as people and who they were, but were also fascinated by each other's bodies.

Xiv had plenty of "hands"-on experience with how Ily (and a couple previous partners) responded but decided to really study the mechanism behind those responses and read up on current theories about what was happening. The structure of the g-spot, the p-spot, the frenulum, nipples, other erectile tissues, whatever, and what they were and different ways to stimulate them. Things got a little clinical for a bit, but it was still playful and "playing doctor" was a good way to pass the time on runs. 

Then when some authors reminded or joked that "the biggest erotic zone is the brain" Xiv had taken it a bit literally. Sure, Xiv understood it was about the psychological component, creating fantasies and engaging with what the other person found sexy or attractive. They got that. At the same time, Xiv was on an anatomy kick and all that psychological software was on some level running on physical biological hardware, right? So maybe Xiv could play with that, right? 

It gave Ily pause. Anatomy was one thing but neuroanatomy was another thing altogether. 

Ily had been understandably reluctant at first to let someone literally inside her head. It had taken a lot of reassurances and forgotten explanations about how it was all temporary and wouldn't damage anything. About exactly how Xiv worked and with practice and focus and feedback what they thought they might be able to do on a cellular level. They had tried to get into the technical details, something about gyrating and sulking, but Ily was pretty sure she had misheard that part. Ultimately, Xiv had convinced her not through the details but the big picture: The very last thing Xiv wanted to do was hurt or unwillingly change Ily. Trying this was scary, but it was also exciting and ultimately it was about trusting Xiv. And Ily did.

Even with all the reference materials the info-net could provide, it was still a lot of trial and error, but that just meant spending more time together, which was the opposite of a problem. It was weird and at first there was silly stuff, like making her arms jerk, or fumbling at making her see or hear random things. Xiv just kept working on it though, obsessed with exploring the possibilities of what they could do; both of what Xiv was physically capable of doing and of what responses they could get from Ily. Ily loved seeing that focus and drive in Xiv as well as Xiv’s devotion to her, and she didn't have to do anything to support her partner but let her in and answer her questions. So she did.

Of course after Xiv started to get a handle on things, participating became much more interesting and its own reward. Literally, in a few cases; remembering the first time Xiv had found her pleasure center still made her pussy wet and her erection tighter every time she thought about it. The literature seemed to suggest that that kind of raw, blunt reward could be addictive, so they had only done it a few times, but there was plenty of other grey matter for Xiv to play with.

Visual processing, physical sensation, memories, drives, fantasies, all of them were somewhere in Ily’s head and Xiv had just had to root around to find them and what could be done with them. It wasn’t just about trying things, and how to stimulate or suppress areas. It was also exploring the mind in that brain and how Ily specifically responded. What sensations affected her. What inhibitions held her back. How to create imagery that turned her on. What could Xiv do in Ily’s head that they couldn’t do from outside it?

It had been immensely rewarding for both of them. Ily had felt and seen things that weren’t possible, and were super hot and tailored for her. Xiv had her own unique experiences of having a partner being so vulnerable and letting Xiv do things to her that no one else had or even could. Doing those things for Ily was a rush unlike anything else. 

It was very demanding though. It was worth it, but it took a lot of attention and precision. After that initial exploration, once Xiv had practiced and gotten the hang of it, they had added it to their repertoire and used it sometimes. But it had been a while.

Now, it seemed like just what Ily needed.

. . .

Xiv tenderly traced a pseudopod around Ily's ear, gently, lovingly tucking her hair out of the way. Then they slithered into yet another of their lover's passages. 

While slow stroking inside and out continued down below, now there was also an insistent pressure inside Ily’s head. The sounds of their coupling and her own gasps were muffled and changed as both her ears were filled with more of Xiv. She felt the slick warmth and fullness from below but now up there in her head. Felt it questing and trying and aching to fill her even more. Felt it pressing and pulsing trying to find an entrance, a way further in. Then, somehow, they did. There wasn't any pain but somehow Xiv pushed through, maybe seeping between things, maybe finding some way around, but definitely finding some kind of way in. Ily did remember that she shouldn't even be able to feel anything against her brain, but she could feel the pressure and warmth of Xiv’s body extending inside her skull now.

From her ears, it ran down the inner walls of her skull, towards the mattress, to the back of her head and started to pool there. Started to fill her and flow up into the nooks and crannies as more of her brain sunk into the rising pool of green goo filling her head. But it wasn't just flowing in and engulfing her: it twitched and throbbed and moved with intent. It wasn't a smooth flow, or even the pulsing of being fucked into her head. It was a background static of countless little pinprick movements and fleeting odd little sensations as bits of that pool coalesced and reached up into her and branched and branched and branched into ever finer threads that delved into her, permeating her further. Probing the innumerable tiny connections that made her her and finding the right ones to seize and start tweaking. Impossibly fine threads weaving themselves into the tapestry of her neurons and changing its pattern. It pumped in through those tight passages, flowed down into her, filled her more, and then dove deeper into the folds and convolutions of her mind to do as Xiv willed there. 

As the level crept up towards her ears, tendrils insinuated themselves into her in specific places and vivid images started to flood her mind. Images of what was happening and what she fantasized was happening. Of her lover's green goo coating her brain in a warm embrace. Of big gooey cocks, literally fucking the brains out of her head. Squeezing into her ears somehow and shoving her out. The cocks meeting resistance and pushing past it to go balls deep into her head. Pulling back farther than there was room for and then slamming back in, again and again, fucking everything away. Of them filling her skull with a pair of probing, throbbing phalluses. Of them lodging into her as deep as they could and pumping jet after jet of hot cum into her, washing the last of her brains away and bursting out of her as she lost control. Of her brains being fucked and melted away, with all her other thoughts and restraint. No thoughts left except the need to be fucked and filled.

She could see it so vividly as her eyes unfocused and her arousal surged. Her breath caught. Her back arched. Her erection tightened and her cunt slickened. 

It was exactly the response Xiv was hoping for, but it was just the beginning. They egged her on even more, speaking softly but directly in her ears.

"That's right, you can feel me not just fucking your gorgeous body, but your beautiful mind as well. Filling you up with me. Ah. All those lovely visuals."

All Ily could do was arch more and moan as she felt more of Xiv coming in.

"But let's get a little more, unf, physical."

As she felt it fill up past her ears, and infiltrate more of her, she did feel her body changing. At least the feelings from her body were changing. Even with everything happening to it, her body started to relax. The tension started draining out of Ily, leaving her loose and open. It was like being a puppet someone was slowly cutting the strings off of, letting everything go. Almost everything. Everything she had control of loosened and went slack, while all those involuntary contractions and spasms and engorged throbbings remained and heightened. It didn’t just create a dramatic contrast, but also highlighted her increasing sensitivity. 

As she lost the ability to move, the feeling of what was happening to her more than made up for it. It took the difference in her attention and then some. Xiv was already everywhere and all of it became more intense and enjoyable. If she could've moved, she would have jerked with every touch, every caress. It was so much. It was almost too much, but not quite. It was being blindfolded in the dark, full of teased anticipation, waiting, and then a lover's lightest touch being  a thunderbolt. Except it was like that with every touch, and she was being touched all over.

She was mewling putty in Xiv's clutches. Even the slow thrusting felt more intense, building more than it had before. 

And now she could feel her brains being fucked, too. It was like a dream, like feeling the ghostly sensations over your actual sleeping body. Now, over the previous suggestions of pressure and filling up her head, there were much more detailed feelings to match the earlier visuals of Xiv fucking into her brains. Of her head tight around the firm, thick, gooey cocks forcing their way in and everything else out. Pulling out only to slide in deeper and harder the next time. And the next. Of every inch penetrating her and pushing in, like her other penetrations but not. Deeper, better somehow. Of them pulsing and spurting hot, sticky cum into her. Filling her up, flowing into the gaps between the hard shafts and then creating more and more pressure, pushing everything else out. She could feel her head being completely filled with throbbing cocks and a rising tide of hot cum. So deliciously filled.

Ily couldn't push back into it, could only cry out briefly as her eyes rolled back and she breathed raggedly in time with Xiv's thrusting.

Ily’s whole body and mind thrummed. She was so close.

She teetered on the edge as Xiv pushed her up to it and held her there.

She didn't even notice when the warmth and pressure finished filling her skull and hit the back of her forehead. She was too far gone to notice her mind following her body and losing all its control and restraint. There was nothing outside of this. Nothing else to care about, no ability to form worries. There was just now and feeling good. And she was feeling so good. 

"There, that's better isn't it?" Xiv husked directly into her, vibrating deliciously.

Ily didn’t answer.

If she could've still thought, she'd have been surprised Xiv wasn't leaking out her eyes and nose by this point. She felt so full. So filled. But that was a thought that wasn't pleasure and release and how good it felt everywhere and how much love she had… so there was no room for it right now. 

Ily wasn’t about to cum. 

She had. She was. She continued to.

Her cunt spasmed and creamed around Xiv. Her ass contracted with it too as Xiv kept thrusting into both and driving her on, prolonging the pleasure. Ily’s rigid cock pulsed, spurting jets of actual, non-hallucinated hot jism into Xiv. They shot out and were suspended, pearly streaks floating in rhythmically flexing, translucent gel. 

The corners of Xiv’s open panting mouth perked up as they savored success. In Ily’s head, feeling her finally let go. In their own body, feeling Ily wracked with pleasure and release. Xiv basked in their lover’s response, all of it a joy. They kept their unrelenting rhythm, milking every drop of pleasure and release out of the otherwise limp Ily. The first pearly streaks diffused and dissolved away as fresher, sharper ones took their place. Xiv licked their lips as they were absorbed, enjoying the taste and heat of it in their body. 

And they kept going. 

Doing their best to keep Ily at that peak and extend it as much as possible. 

All Ily could do was ride along as everything happened to her and her body responded on its own. It was too much. Her eyes were rolled back, her jaw hung slack, and involuntary twitches spasmed occasionally, but she wasn't really there anymore. There was a low keening whine of need, and other noises, but they didn’t seem intentional. She was unresponsive but faintly smiling. 

“There you go. (nf) No more worries (nf) or thoughts (ah) or cares. Just feeling good. (ah) So let's see (unf), how good we can feel. “

As Ily turn to figurative jelly beneath the attentions of Xiv's literal jelly, they kept fucking away. Fucking away everything hurting their adorable Ily. Fucking away everything that didn't feel this fucking good. Fuck, when Xiv was in Ily's head like this they could practically feel what she felt. Ily'd been overwhelmed to unresponsiveness, and that was hot in itself, but Xiv could still feel those ongoing pulses of sensation in Ily's head. Even if Ily couldn't express what she felt, Xiv knew just what she was still feeling and it only added on top of how Xiv was already doing (which was pretty fucking amazing, thank you very much).

There was no one watching their face, but the habit of expressing themself there was ingrained deep by now. While Ily was totally relaxed, Xiv's (just for show) eyes clenched and their brow furrowed in concentration to keep going. Their body churned as it expanded and contracted around their lover, like a heart pumping from exertion. Pounding, pumping so hard you feel it through your whole body.

However, even habit fell under their drive to keep going. Their need to keep going, to keep working their bodies, to only care about where the two of them met and how they felt. To let everything else fall away and push their limits to make this last as long as possible. Xiv started losing definition, that expressive face fading into a lump of a head and then that faded into the larger mass. Back and hips and lips and fingers devolved into just tendrils and masses, only defined enough for what they needed to keep doing to Ily, keeping that same rhythm, never losing that rhythm, Xiv working to exhaustion riding the high of how it felt and how Ily felt. Pumping and pumping and pumping away.

Any body gives out eventually, but it's amazing how long you can last when it feels that good.