My part of a trade piece that got away from me a bit. 3546 words.

Rung (i.e. small orange robot nerd from MTMTE) and Alzu (my wolfy OC) having a good deal of fun. 

(I’m fairly sure Alzu and Rung are quite close in size. If they aren’t, the difference is minor, and Alzu calls people ‘little one’ based on how they act more than their size compared to him) 

 No significant warnings, but contains rough sex, some careful biting, knotting, and someone rather getting off on their partner not being the same species as them. All participants are sapient and thoroughly enthusiastic, and discussion about boundaries has occurred beforehand. Additional content includes oral sex w/ a long tongue involved, some dirty talk, some slightly clumsy aftercare, a small break to ensure one partner’s comfort, and a very flustered nerd. 

———————– 

“Oh- goodness.”

That was… a bit bigger than expected, all things considered. A bit cautious, Rung wrapped a servo around the shaft being pressed into his palm, stroking gently over the intriguing textures. At an insistent whine, he tightened his grip a bit further, still careful-

And promptly had all his coherence shoved away as teeth nipped at his throat. A long, broad tongue slipped out to lap at the tiny nicks, and Alzu insistently pushed Rung back in a very nice illustration of his strength. Granted, Rung was technically stronger, but the psychiatrist went with it, making a soft noise as his throat was nipped again.

Alzu bit gently at Rung’s throat, just enough to scrape and
leave tiny marks, then switched to licking the marks as he gripped those narrow
hips to get them positioned. Already drooling a bit and quietly hoping his
Cybertronian partner didn’t mind, he lapped and bit his way down Rung’s front,
leaving a trail of damp spots and small scratches, and lingered on that
pleasantly soft stomach before pausing to stare up at Rung, pant, and wag his
tail as blatantly as he could.

Rung, already covering his mouth with one servo, shivered
lightly at the intense stare being aimed up at him. He didn’t mind the dampness
at all, in fact it was surprisingly hot, and there was something surprisingly
tasty about having a partner stop just above your hips to look up at you
before-

“Oh my-“

In this case, the plan was apparently to lock both nice,
strong, soft-padded hands  around Rung’s
hips and shove that long muzzle between his thighs, pushing his legs apart and
exposing his pelvic plating to whatever Alzu wanted to do to him. Which,
apparently, involved a lot of licking with a beautifully soft tongue.

Fans already whirring, Rung squirmed against the powerful
hands holding him down, uncovering his mouth in favor of gripping the sheets
under him. “Oh dear, oh Primus- that
is- oh my. I-I- oh dear- do be gentle, please, I’m- oh, you’re very strong,” he squeaked, hips twitching away from the
insistent lapping, and shivered all over as Alzu growled.

Truthfully, some of that was acting. That was the role he
was taking here- vulnerable, trapped, the flustered little prey of a powerful
hunter. Not that it was a difficult role to take, goodness, he was certainly very
flustered and somewhat trapped, but- oh,
Primus, this was a very nice role
to play. He didn’t need to worry about keeping his composure or remaining in
control of the situation, he could just relax, open up, and let himself be ravished.

 

Snarling in delight as Rung’s pelvic plating snapped aside,
Alzu pushed his muzzle into a gorgeous orange valve, lapping at the shimmering
blue bio-lights to see what kind of sounds he could get. More flustered
squeaking, mostly, plus a delightful squeal as he lapped over Rung’s brightly
glowing node. Lifting his head slightly, Alzu let his jaws hang open and his
tongue loll out, drooling lightly as he stared up at the flustered little mech.
“Oh, lookit you… so, so pretty, li’l
trophy. Gonna make ya squeal f’ me again, pretty, an’ much louder next time-
gonna fuck ya real gentle, first, then flip y’ over an’ pound you.”

As he spoke, Alzu slid both hands up to grip at Rung’s
thighs, pushing his legs apart so he had no way to shield himself from
everything. “Gonn’ fill y’ up, make y’ squirm, make y’ scream f’ me, an’ you are gonna love every second of it, li’l pretty… gonn’ have some fun.”

With that, he grinned wider, lowered his head, and set about
making Rung squeal again.

It did not take long.

“Oh- oh dear, I- oh- dear Prim- ah-“

Rung’s vocalizer glitched out for a moment, which only
served to make him even more flustered
as he got an audial-full of the wet, lewd
sounds of that long, powerful tongue buried in his valve, and he let go of
the berth with one servo in favor of covering his mouth. That didn’t do much to
muffle the sounds he was making, though- nor did it stop Alzu from lapping
deeper in an attempt to earn more noises.

Gasping softly, Rung squirmed against the powerful hands on
his thighs, legs twitching where they were tossed over Alzu’s shoulders.
“Primus, Alzu- oh, I- more-“ he managed, then whined in
disappointment when Alzu responded by taking his muzzle away. No, that was exactly the opposite of what Rung had requeste-

OH.

More? He could do that.

Alzu growled softly and slunk up Rung’s frame, licking and
nipping at his front until he could stare down at his partner’s blushing face.
And, more importantly, could grind his cock against that pretty valve. “Y’ wan’
more? Give ya more, gorgeous- gonn’ fill y’ up. Don’ worry, though, li’l one…
gonn’ be gentle. T’ start off, anyway. Start off wi’ makin’ you whimper ‘fore
we get t’ th’ squealin’.”

Nuzzling softly at Rung’s throat, Alzu slid one hand down to
guide his cock into place, pressing the tip into Rung’s valve to make sure he
was lined up properly. “Yeah- ain’t you a hot li’l thing. An’ you smell nice, an’ all th’ sounds- so good. Yeah? Y’ hear? Yeah.”

Alzu closed his jaws gently around Rung’s throat, just
enough for his teeth to be felt, drooling shamelessly against the muscle
cables, and rocked his hips in a teasing little thrust- trying to see what he
could get out of Rung.

What he got was a soft, pleading whine, accompanied by
Rung’s servos clutching at his back. Flustered or not, Rung wanted more. More of that tongue would be
great, but, if not- he wanted to try out the shaft that he’d gotten a fleeting
look at earlier. Interesting textures, a good shape, and a proper knot- dear Primus, yes, he wanted. What- was Alzu going to make him beg? Because
he just might, at the rate things were-

Ooh, no, there-

As promised, the first thrust was gentle. A long, slow
rocking motion, spreading him open around a shaft with a thoroughly alien feel, and-

Oh, right, he was interfacing with an organic. Not that Rung
had anything against organics, but this was a very naughty thing to do by just about any standards, and he was
enjoying that thought far too much.
And enjoying the rolling thrusts far more, oh dear, that was an amazing sensation.
Hot and wet and throbbing, stretching
him open, accompanied by the sensation of teeth shut around his throat and soft
fur against his plating-

Definitely an organic, and a very attractive one, slag him.

Muttering “oh dear, oh my” to himself, Rung wrapped his legs
around Alzu’s waist, trying to give
himself some leverage to thrust up and meet the slow, careful rocking. It
didn’t work out so well, though, because he had to cover his face in both
servos as Alzu kept talking. This big
fluffy thing was making him blush to
an embarrassing degree-

Alzu hooked both hands under Rung to pull those skinny hips
into his thrust, increasing his speed, and let go of his throat in order to
speak clearly. “So hot, so tight, so good-
yeah, y’hear? Doin’ a good, good job-
ah, yeah, cute li’l legs, lemme feel ya- yeah.
Ah, good li’l mech, good Rung- aw, now, move them li’l
fingers. Wann’ see y’ face, an’ y’ gonn’ have t’ brace y’self if y’ wan’ more.”

Licking at Rung’s servos in an effort to coax them aside,
Alzu whined quietly in encouragement, then grinned and thrust harder when the
little mech started to comply. Positive reinforcement- the more he could see of
Rung’s face, the harder he thrust. “Heh, yeah- feel that? Y’ lemme see ya, I
see ‘bout makin’ y’ squeal. Ain’t no shame here, Rung, ‘s jus’ fun. C’mon, pretty- oh! I see- is tha’
it? Y’ get flustered an’ hide when I call ya nice things? Aw- ain’t you jus’
th’ sweetes’ li’l thing? Oh- make y’ a deal. Y’ move one servo outta th’ way- I
fuck y’ nice’n hard. Y’ want?”

Apparently Rung did want,
as he whimpered quietly and moved one servo out of the way to grip the sheets
again, though he was still hiding behind the other.

“Aw, yeah- there we go, lemme kiss y’ li’l face.” Alzu
muttered, licking messily over Rung’s cheek, then grinned and set about
fulfilling his part of the deal.

Oh dear, that was an accurate statement, but Rung had
no time to think about the implications before a well-timed thrust stole any
fragments of coherent thought that he might have been able to manage. “Oh- oh
dear, oh my, oh goodness, thank you, that- that is- ah– Priiimus-“

Well, Alzu had certainly made good on his promise to make
Rung squeal, but Rung was in no position to mind in the slightest. Or,
honestly, do anything but continue making sounds that only seemed to turn his
partner on any more.

It was kind of embarrassing how fast his charge was
building.

Alzu had played with Cybertronians before, so he knew what
building charge felt like crackling against him. It would be an issue for a lot
of organics, but, aside from a vague scent of heating fur, it had no visible
effect on Alzu. He was a Lyca, after all- difficult to hurt. Lowering his head,
he grinned and panted softly in Rung’s audials, trying to see if he could
fluster the cutie any further. “Wrong name, li’l sweet. Ooh- fuck, you gotta strong valve, you know
that? Ain’t tight, you are hella turned
on by bein’ fucked like this, bu’ strong.
All that nice clampin’, an’- ooh, yeah,
you like me praisin’ you, yeah? Clamp
down ‘round me when I talk ‘bout things like how gorgeous y’ are. An’, you feel that? Y’ takin’ th’ knot now, good mech, an’ y’ got no problems- still
all wet’n tightenin’ down real nice on me, an’makin’ those good noises, yeah- makin’ you feel real good,
hm? Aw- don’ need ta tell me, I can feel ya- gonn’ come real soon, huh? Good-
let’s feel ya. C’mon- c’mon, lemme feel ya, lemme hear ya- c’mon, Rung, y’
gorgeous li’l thing-“

“Oh Prim- aah- nnh,
Alzu- frag-“

Rung dug his fingers into Alzu’s back, legs wrapping tighter
around his waist, and gave up on keeping himself quiet. He hadn’t been managing
it anyway- not with those lovely textures stroking over his inner walls, that
smooth bulge sliding against his valve rim and working it open further, and the
things Alzu was saying-

And Alzu kept talking,
started thrusting harder whenever
Rung said his name, kept thrusting-

Rung’s thighs clamped around Alzu’s waist and he keened as overload crashed over him, valve
clamping and rippling against Alzu’s length.

“Ye-he-heah,  baby- that’s
it!” Alzu howled and kept going through Rung’s overload, quick, shallow
thrusts, drawing it out as long as he could before he also came. When he did,
he made sure to keep himself in control, specifically his knot- he didn’t want
it to expand all the way, not yet. And he’d had enough practice at this for it
to work- his knot expanded slightly, just enough to keep most of the fluids
inside, but not enough that he wouldn’t be able to pull back out.

Still drooling, he licked clumsily at Rung’s chassis
plating, enjoying the flustered wrigging underneath him. “Ooh, yeah, cutie…
gotcha. What’cha think? You like this? C’mon now- ya tell me.”

“Ohh, goodness… yes.” Rung admitted, very quietly,  and whined
when Alzu pulled on where they were joined together. “Oh my- oh, I-I see what you meant ab-bout- oh, o-over? All- all
right-“

Dazed, but happy to play along, Rung obeyed the insistent
nudging and tried to flip over. It took some careful moving, given that Alzu
was still inside him, but Alzu didn’t seem to mind- the knot slid easily
enough, there was no twisting. “Oh- oh dear. I may, ah- oh, you are- goodness,
you are energetic, and I- a-a moment,
please? Just to- oh- to rest, especially since… since we plan- plan to- oh.”

 

“Mmr, I gotcha. Easy- y’ can rest. Shh- gotcha.” Alzu
rumbled, lapping carefully at those cute antennae, and settled against Rung as
he reached for a pillow. “An’, now- we don’ haveta play rough a’ all if y’ don’
wanna. M’kay? ‘S okay t’ not.”

Licking gently at the back of Rung’s helm, Alzu pulled a large
pillow over and lifted the small mech’s hips with his other servo, tucking the
pillow underneath to keep him propped up.

“No, I- nnh, oh, I do want
to, um- to do that, I-I only need a klik to rest, if you don’t mind.” Rung
managed, though it was a bit muffled due to him having his face in the berth.
Considerate of Alzu, and certainly a good thing to hear from someone currently
sheathed in his valve. Some time to gather himself up and vent deeply, to let
his charge build again before-

Well, goodness- he was in for something rather tiring,
wasn’t he? But it was very, very exciting.

So he waited for just a klik or two, until his charge rose
and the anticipation became too much to bear, and then braced his servos on the
berth and deliberately rocked back against Alzu. “Alright- ready.” Rung
ventured, then squeaked as Alzu
immediately clamped down on the back of his neck.

Alzu growled in a way rather like an engine revving, biting
at Rung’s scruff, and used just enough pressure to lift him for an instant
before letting go. Lapping messily at the spot he’d bitten, he began to slowly
rock his hips against Rung, feeling things out as the knot slowly shrunk back
down. He’d managed to hold back the first time he’d climaxed, which meant,
well- things were going to continue, and they were going to continue quickly,
now that Rung was ready for him. Because Rung was quite obviously ready, in every sense of the word- frame
largely relaxed save for where he was bracing himself against Alzu, valve dripping
wet and spreading easily around each increasingly deep thrust. Most
importantly, he was excited- blushing,
hiding his face, but pushing back against Alzu and making delightful noises in anticipation. He was turned
on, he was ready, he was more than willing- perfect.

Alzu withdrew slightly, paused for an instant, and then thrust as deeply as he could in one
quick, smooth motion.

Rung, practically trembling in anticipation, whined quietly
at the withdrawal and quickly followed it up with a squeal of startled
pleasure. And Alzu didn’t let up. Powerful arms wrapped around Rung’s
midsection, and the first thrust was immediately repeated as Alzu set about thoroughly fragging him.

“Oh- oh my- nnh,
goodn- ah, Prim- Pit, Alzu! Ooh goodn- hhah- ah-“

Having already lost just about all hint of coherence, Rung
could only clutch at the sheets and cry out, trying to spur Alzu on and get him
to thrust harder. That lovely shaft
was hitting all the right spots, the
knot-bulge spreading his valve rim wider in a wonderful way, and he wanted more- he could take it!

“Alzu, plea- ah- more!”

More? He could do that, especially with those noises
spurring him on. Just the incoherent sputtering would have been excellent, but
Rung was managing his name, and wasn’t
that just a bolt of heat straight to his cock? Oh yes it was, and he was going
to put that energy to use. Grinning, Alzu tucked his hips under and put every
bit of strength that he had into each thrust, drawing a very interesting squeal from Rung at the increased sensation. All
right then- Rung could take hard thrusts? Well, Alzu would quite happily give
him a proper fucking. Snarling and all.

Giving up on hiding his face in favor of being able to vent
properly, Rung turned his helm to the side, yelping in flustered surprise as
Alzu immediately licked his exposed face. “Oh Prim- ah- yes-“

He wasn’t doing a very good job of coherently expressing
himself, but he was dimly aware that he was making a good deal of
overwhelmingly positive sounds up at Alzu, and that it seemed to be spurring
his partner on.

So he gave up on trying to communicate, shut his optics, and
let himself get lost in the sensation of a thick, beautifully textured shaft
thrusting deep inside him and a warm partner pressed against his back as they
pounded him.

It was not hard to get lost in.

Alzu essentially did the same, though he did have to
maintain a few scraps of control. No more biting, for one, and he had to shift
the angle now and then. Aside from that, he could lose himself- Rung was
durable enough to take accidental claw-scrapes and the hardest thrusts that
Alzu could manage.

So, this time, there was no holding back. When he felt a
familiar tension curling in his belly, Alzu pressed as deep as he could for the
last couple of thrusts, then froze with his cock sheathed in Rung’s valve- back
arched, howling his pleasure loud enough to make the room echo, hips working in
tiny motions as his knot expanded fully and locked them together.

Rung was close at
Alzu’s final thrusts, even closer as the knot spread him open further, but it
was the sounds more than anything else that put him over. Alzu’s howl and his
guttural panting were incredibly
alien sounds, and that, combined with the fur
and the strange-but-delightful texture of his shaft, combined to thoroughly
drive home the point that this was not another
Cybertronian. And it was that, in addition to everything else, that brought him
over the edge. He was a bit quieter than Alzu, but not by much- keening out
what might have been an attempt at his partner’s name.

And that knot, oh-

Whimpering softly in pleasure, Rung pawed weakly at the
sheets, on the edge of sensory overload before the weight against his back
shifted off. Finding himself nearly face-to-face with the being still sheathed
deep inside him, he gave a quiet, flustered little noise, hiding behind one
servo, then reached to awkwardly pat behind his ears. “…oh goodness.”

What else was he
supposed to say to someone who was responsible for his valve being full of
cock, cum, and knot?

Alzu aimed a sideways grin at Rung and flicked his tongue
out to lick the small mech’s nasal ridge, then relaxed, slumped partly over the
other’s frame. “Cuuute.”

But, oh- aftercare.
Important. Right.

“Y’a’ight?” he managed, not certain how coherent it was, and
rubbed gently at Rung’s back with one hand. “Y’likin’?”

Rung tried to pulse approval through his EM field,
remembered that Alzu couldn’t feel it, and settled for quietly moaning in
approval. “Ohh. Yes.”

And Alzu kept trying- kept rubbing his back, curling around
him, shifting with him until they were both comfortable. That was… probably
nicer than he ought to find it, having someone… oh, care like this… and right after fragging him halfway through the
mattress. Contrast.

As his coherence returned, Alzu continued to reposition them
both, curled on his side around Rung so that his Cybertronian partner could
vent properly from everywhere. Lapping softly at Rung’s scruff, he purred
gently and kneaded with both hands at various spots, trying to loosen any tension
or knots. Well, except for his knot,
that was staying. For awhile, at least. Especially if Rung was still happy with
it. And he was, as far as Alzu could tell. Hm, check the face again- yes,
happy! Cue tail wagging.

Rung, thoroughly happy with the situation and too tired for
much, made no effort to change anything. Mostly because Alzu was kneading him,
grooming him- it was delightful. He made certain to emphasize it, too, patting
gently at Alzu’s frame as much as he could.

But, eventually, Alzu had to pull away. Mostly because his
knot had shrunk enough to start letting fluids out, and he might as well get
that over with. “Li’l pull.” He warned, then rocked back, the mostly-shrunk
knot making a quiet popping sound as it slipped out. And then, well- he had to flip Rung over and look down at
him.

Flushed, disheveled, smelling thoroughly like Alzu, and with
cum dripping from his valve- an amazing picture. Sitting back, Alzu grinned and
licked his lips, looking Rung over until the small mech glanced down at himself
and blushed even further. “Yeah- tha’s it. Lookit yerself. Ain’t you all
pretty- all stuffed full, an’ y’ smell like me. Even prettier. Buuut… I gotta
clean y’ all over, yeah? So- hold still, gonn’ have fun.”

With that, he blatantly licked his lips, nudged Rung’s
thighs apart again, and dove in.

 

Quite a lot of time later, Rung lay curled comfortably on
his side, tucked under a warm blanket, wrapped in a soft-furred Lyca. Both had
cleaned up, which meant everything was warm, soft, and comfortable- and Rung
was still getting a massage. Just
about the closest possible thing to perfect for the both of them.