I think you are going to Lego “Ebb and Flow” by @moonwalkingcrab. In the fic, Hux visits a spa where services are provided by gentle tentacle creatures.” Hope this is close to what you were looking for!
I’m sure some more fics will pop up and I plan to draw more tentacle pieces whenever I have time. For now you can look through my curated selection of tentacles under my tentacle tag.
Pasiphae
by @vadianna, 46,748 words, E, No archive warnings. While
depressed one night, Kylo Ren decides to jerk out his sorrows to his
favorite holoporn vids, starring Major Fuxx and his parade of alien
partners. Major Fuxx bears a striking resemblance to General Hux,
which is part of the appeal, but he suddenly realizes that they may
have more in common than their looks…
I
Can Satisfy You
by @specterqueen, 4303 words, E, No archive warnings. Hux
is a xenophile with experience under his belt. Kylo offers to satisfy
his urges. Hux dismisses him as boring and surely not possessing the
necessary equipment. Kylo endeavors to prove that he does not have to
be an alien to fulfill Hux’s desires.
Clutch
by @orange-lightsaber, 4840 words, E, Creator chose not to use
archive warnings. A half-alien Hux is caught in
an embarrassing predicament and Kylo is way too intense about it.
Divided Desire
by @kdazrael, 16,981 words, E, No archive warnings. Hux
felt himself go pale, his muscles pulling tight and scalp prickling.
“Why would I give a damn about what some foul alien has between its
legs?“
Something
Different
by MissMegh,
2118 words, E, No archive warnings. “You
said to me that you are… uninterested in ‘the same thing as
always.’” Hux couldn’t help a slight smile, thin and
vindictive. “I wholeheartedly agree.” (tentacles)
Specimen
by @its-pixiesthings, 4691 words, E, dub/non-con. Ben,
or Kylo as he has come to be known, is Emperor Hux’s own personal
slave, but he’s a little more than a handful to tame. Emperor Hux has
decided to put him through the experience of his life in an effort to
teach him his proper place… (tentacles)
Sucker Punch
by @unicornsandbutane, 6631 words, E, no archive warnings. Kylo
hacks Hux’s datapad, trying to find out if there’s anything the man
actually likes. He finds something. It’s not what he was expecting,
but he can work with it. (tentacles)
Call of
Kylthulhu
by @white-rainbowff, 2828 words, E, light body horror. Kylo does something romantic
for Hux involving Science! (Kylo’s idea of romantic is slightly
different than Hux’s) (tentacles)
Tagged by @reserve to create a moodboard for a fic! Thanks for thinking of me. ❤ This was SO much fun, I’m gonna be doing shit tons of these ah ha ha.
This (as you might have guessed) is for Sucker Punch :
At that moment, the container trembled, and Hux stumbled back. “What the kriffing hell have you brought in here, Ren?!” he hissed, as the box shook again before falling still.
“It’s precisely to your tastes, General,” Kylo promised, unable to keep the grin from his face. “I spent three standard cycles hunting it down. I had to do it carefully, you know. Had to find one that was the right size, and at the right stage of development.”
“What. Is. It.” Hux grit out, and Kylo finally gave in and opened the box. He would’ve liked for Hux to do it, but the look on Hux’s face was almost as good, when the first shiny, red-purple limb curled out of the depths of the container and began feeling around its outside surface. Hux’s eyes had gone wide. His face had gone pale, except for two high spots of colour on his cheeks. He licked his lips, and did not blink.
Another tentacle flopped out of the box, and then a third, a fourth, and then the body of the creature emerged. It had no visible eyes, and was no larger than a BB unit, but sensed the world around it with a pair of long antennae near the front of its body. It was slick, and its body was bulbous, gravid even, and overall it was not a particularly attractive thing, nestled among its six twisting arms. Hux was looking at it like it was Life Day morning.
“Do you like it?” Kylo asked, stepping around the desk to be closer to Hux.
“I…” A complex reaction seemed to be taking place on Hux’s face. “Why would you… I can only assume you’ve managed to get into my mind. Is this blackmail of some kind? Are you trying to shame me?”
His face was dismayed, but he didn’t seem to be able to access his usual vehemence. His eyes remained fixed to the creature as it read the room with minute waves of its antennae. Kylo hadn’t prepared for this reaction.
“I didn’t take it from your mind,” he said. “I’m not trying to degrade you. I’m… offering this to you.”
Finally, Hux turned, laid the full weight of his state on Kylo. “Why?” he asked, searching Kylo’s face. “Why would you do that? What do you want from me?”
“I was hoping you would let me watch,” Kylo replied, forcing himself to hold Hux’s gaze. Hux gasped when the realisation hit him, flicked his eyes frantically between Kylo and the creature. The silence grew thick, and Kylo nearly reached out for Hux’s mind on the off chance his distraction would weaken his façades enough that Kylo could actually get something out of him, but then Hux stripped his gloves, and raised his hands, pale, sweaty, to the collar of his uniform.
dispatches from the dumpster 