Posted originally on the Archive_of_Our_Own at https://archiveofourown.org/
works/7085998.
  Rating:
      Explicit
  Archive Warning:
      Underage
  Category:
      M/M
  Fandom:
      Undertale_(Video_Game)
  Relationship:
      Papyrus/Sans, W._D._Gaster/Papyrus/Sans
  Character:
      Sans_(Undertale), Papyrus_(Undertale), Grillby_(Undertale), Undyne_
      (Undertale), Alphys_(Undertale)
  Additional Tags:
      Scientist_W._D._Gaster, Good_W._D._Gaster, W._D._Gaster_is_not_related_to
      Skelebros, Freakshow_au, but_not_the_evil_story_line, Gaster_has_a
      fobwatch, conjoined_skele_brothers, Threesome, Ecto-Penis, Ecto-Tongue,
      this_doesn't_really_take_place_in_the_freakshow_timeline, Written_For
      Fun, Conjoined_Twins, Cunnilingus, steampunk/victorian_age_era
  Stats:
      Published: 2016-06-04 Words: 3855
****** On my sweet sixteenth, will you take me to the circus? ******
by othersin
Summary
     Dr Gaster visits the travelling circus for the skeleton brothers
     sweet sixteenth - the inhabitants of the freak show always enjoys his
     company as he has decided to give them something very lovely on this
     special evening...
  
===============================================================================
Gaster adjusted his coat and hat, pulling out his fob watch and checking the
time for his next appointment – the click-clack of his leather shoes and the
tap of his umbrella against the stone path was the only sound echoing on this
lonely road, by the foot of Mt Ebott, the forest was the only barrier between
the barren, earthy mountain side and to the fertile, green villages and farms.
He carried a leather case, for his equipment - a doctor’s case.
He was a specialist in abnormalities of the body and mind, inflections and
mutations present in both human and monster alike – the royal scientist of the
Monster royal court. As a high ranking member of the monster court he could’ve
got a cab to take him to his next appointment outside of the palace; but this
was a personal appointment which he didn’t wish for it to be known to any of
the nosy courtiers desperate to knock him down from the pedestal that King
Asgore placed him on.
 Besides, if any wayward humans or monsters decided to attack him – he could
easily dispatch them; while he and most other monsters have accepted to live
side by side with the humans after a 100 year war, there were still those who
wish to cause trouble for both monsters and humans. Creating anarchy in the
brittle peace and truces, lone roads like this was notorious for humans –
highway men to rob travellers.
 Especially because of where the road was leading too.
As he finally crossed the bend, he could see the large red and white tent
poking up in the distance – a flag billowing in the night breeze, and fairy
lights stringing between the tents and carnival poles; the last drunken dregs
were stumbling out, hollering to a showgirl walking about in a frilly skirt and
fishnets, her small bosom pressed tightly in her corset – skin brightly painted
with tattoos and ink. She ignored the men and continued to help pack up for the
day.
A lean fire monster was helping her pack away props and put away the sideshow
games for the children – talking about children, there were two brown haired
twins and one goat monster child aiding the best they could but it was the
adult’s job to take care of the heavy props. Gaster could still smell burning
toffee, apple and something so pungently carnival scent – sweat, tears, animal
dropping and the heavy scent of gin or rum.
The men stumbled past him laughing hysterically, all in clothes befitting those
of chimney sweeps or miners – the stench of their drink was so powerfully
repugnant that it made the elder skeleton believe they may have come in drunk.
Gaster ignored them and continued on his way – feeling his nerves rise up a
little. It had been a long time since he has been able to see them …his palace
duties had gotten almost overbearing that he was only able to visit on the
final days of the circus touring around the mountain and carefully avoiding
suspicion from his peers.
To his peers, he was a monster born into money – and had inherited the money at
his parents untimely demise, and like all young gentle monsters at the time he
was expected to go to university and find the loving and nurturing mother of
his future children.
He pursued his education though didn’t bother finding his lifelong companion
during his studious years unlike some of his peers, but that didn’t stop the
young monsters try and convince him that they could be the one. He then met
her, Helvetica, a well-breed skeleton – gentle and polite, enjoying piano and
walking in the rain… Gaster wouldn’t say he loved her, but he was immensely
fond of her – unlike other ladies of high station she seemed to enjoy the
sciences and arts unlike those foolish creatures that bat their eyelashes and
overzealously fan their faces.
It was a mutual agreement that they would wed in the summer of the year when
Gaster had secured a position in the court, a student under the former royal
scientist and a family name as well-known as his – he was sure to get the
position he craved so desperately, Helvetica fuelled his ambition even more so.
Everything that Gaster wished for and what was expected of him was coming
together perfectly.
But the winter before the summer…the cold hit down harder than it had ever done
before, his sweet Helvetica was always prone to wonder about for far too long –
losing herself in a novel she was reading or the lovely snow-capped landscapes
around their home. It started off as a cough, then the hacking up of ectoplasm;
she was then bedbound half delirious with fever – Helvetica tried to pretend
not to be that ill in the beginning, wishing him to succeed with a smile on her
face; Gaster’s ambition truly blinded him to the fact that she was slipping
right between his fingers.
In fact, the first time he came to the circus was when Helvetica’s dust began
to slip through his fingers as he stroked her smooth skull one last time. Her
family blamed him, and that was fine with Gaster – he allowed them to place her
dust on her favourite book, a title he had seen Helvetica read and trace the
embossed letters on the leather bound book when they had sat together. But he
was sad to say he found he couldn’t care to ask her about it – it still held
little interest to him, so with the cold glares of the others Gaster found
himself ambling down the same path he took in the future – a half empty whisky
bottle was clasped in his hand and looking like a wreck.
Gaster finds himself lost in his melancholy memories as he walked surely the
same path he did the first time he came here – drunk and bitter, he had an
aggressive encounter with the fire monster which had stopped what he was doing
and stare at the lanky skeleton, wearing fancy clothes looking very much out
place next to the fire monster who wore brown pants, suspenders and a stained
white shirt.
‘Good evening.’ Gaster began; every time he came here he felt on edge at the
others glasses glaring at him. The fire eater, Grillby recalled his first run
in at the circus all too well.
Grillby crossed his arms, and the tattooed girl walked up to Gaster, probably
out of pity,
‘Are you after Sans and Papyrus?’ she gently asked, as it is common place for
monsters of the same breed to look for their own kind. Gaster couldn’t fault
the girl for assuming he was looking for the only other skeletons.
‘Yes – I am their doctor and physician…I had meant to see them earlier in the
month but everything seemed happen all at once.’ Gaster explained without
revealing too much, but Grillby only glared harder at the scientist but keeping
silent.
 Grillby was a monster of very few words, but he knew what was going on.
‘They should be finished their shows today, do you want me to get them?’ The
girl said.
‘No, I’m sure they’ve had a long day – I’ll rather go to them instead.’ Gaster
explained carefully, he only usually ran into Grillby at this time.
She looked slightly uncomfortable and stared at Grillby and then back to the
elder skeleton,
‘We’re not really supposed to take outsiders to their private residences… I’ll
have to talk to the ringmaster…’
‘Ah, I perfectly understand – the privacy of your performers is of the utmost
importance.’ Gaster grinned kindly at the tattooed girl, only being surprised
when Grillby cut in with his raspy voice,
‘How much do you got on you?’
Gaster instantly dropped the act and seemed to go into business mode, the girl
looking stunned at the sudden change. Grillby and he had always done it this
way, even when demanding the other to show him something interesting when drunk
the fire monster shrugged and asked for a bribe.
‘5,000 gold – if you take me to Sans and Papyrus without alerting the
ringmaster, you can split it.’ Gaster pulled out the bag of gold, the girl’s
eyes widening even more and Grillby nodded.
===============================================================================
 
The poor tattooed girl was on edge as she led them through the maze of dimly
lit caravans – jumping at the smallest of sound. Gaster wondered if she were
new, Grillby was a calm glowing light – bringing up the bright colours of the
painted trailers for a second before it plunging into darkness once again.
They had come to the far side of the grounds were a familiar caravan loomed –
it was as festive as the rest of them, though stringed with Christmas lights
which flickered and sparked. The tattooed girl had then promptly run off,
Grillby soon followed but at a slower pace.
Gaster stared at the wooden door, giving it a light tap – two voices calling
out,
‘Come in!’
Gaster opened the door, and almost fell out of the caravan as he was bombarded
with two pairs of skeleton arms wrapping around his waist, Gaster steadied
himself as the two smaller skeletons nuzzled into him –pulling himself inside
and shutting the door, on the glaring Grillby
‘Gaster, what took you so long?’ the taller one huffed
‘We missed you…’ the smaller one whispered.
‘I’m sorry boys – the palace has been hectic.’ Gaster placed a fond skeleton
kiss against their skulls – trying not to linger too long, but they must’ve had
a bath; they smelt like the bath salts he gifted to them before. They smelt
nice…
‘You missed our birthday…’ The skeleton teenagers huffed annoyed.
‘Ah, I know I missed it but how could I forget your sweet sixteen.’ Gaster
smiled and opened his doctors bag pulling out two gifts for the two young
skeletons – they were bright and happy, well treated in the circus; they could
pass as two normal children besides their one flaw…they were joined by the
spine and had only one pair of legs and pelvis.
They were an odd case, as usually it was only identical twins that this
occurred with in human and monster cases – the best he can determine is that
the boy’s mother (god rest her soul) was near high amounts of determination
throughout the gestation period, at a period in the infants life when the souls
started to create bone matter to protect the small infant souls.
The boys did not like talking about her – and had hit Gaster when he had asked
too many questions, he knew them since his early 20’s from when Helvetica
passed away – they were the ones who nursed him back to health from Grillby
beating his drunk arse to the ground. So he knew them when they were just 6
monster years – the ringmaster had explained that the boys were abandoned by
his tent as the mother was close to dusting. He had done everything he could
for the female skeleton but sadly, it wasn’t enough.
Upon finding out that the Gaster was a doctor, he conceded rather than pressing
charges or making the court know of his rumbustious drunken escapade – he asked
the other to look after any of his freaks shows medical concerns. Gaster
heartedly agreed – keen to learn more about the skeleton brothers, his interest
shifting from friendly affection to heated thoughts about the two skeletons as
they grew even more handsome though the years.
Gaster had felt affection and appreciation for both the male and female form –
though finding solace in the male sex was something not discussed in the
streets; a few of his peers had felt the same but to keep up pretence they wed
a woman and had a male lover. Gaster wondered if Helvetica realised she
would’ve married a man with these thoughts, she still probably would’ve wed him
still – she was very similar in mindset to him.
Gaster smiled when Papyrus ripped into his gift – revealing to his delight a
bright red scarf and a portable chess set, as the other showed a keen interest
in military strategies and puzzles. Gaster would show them how to play of
course, he was sure that he received his own chess set when he was the same age
as the boys.
Sans got a couple of the newest copies of the textbooks, so both he and Papyrus
would be able to learn about the world  - Sans in particular was very
interested in the sciences and enjoyed the arts, so he got the other a sketch
book and some graphite’s to draw with. Also a new book of puns which would
annoy Papyrus but Sans would enjoy.
‘Wowie! With this scarf, I’ll look like a knight.’ Papyrus hugged the woollen
fabric close to his face, Sans picked up the joke book with an amused and
mischievous glint in his eyes, looking towards the doctor with a smile and a
small thank you.
‘Thankyou Doctor Gaster – this is the best birthday ever!’ Papyrus chimed
happily at their benefactor.
‘But they aren’t really sweet sixteen gifts are they…’ Sans began, Papyrus
staring dumbly at his brother but instantly flushing with a nervous smile,
‘I-I suppose that is true…when the others turned 16 they usually have a special
someone for the night.’
Gaster flushed at the heated glance of the twins, being brought up in a society
where monsters were shamed at being blunt with their affections – what the
others were implying sent a strange thrill down his spine. But almost being 20
years their senior was not a problem in this day and age, many gentleman and
monster would take a wife at the same age as the boys but he wanted them to be
certain this is what they wanted.
‘I would never be able to wed you.’ Gaster began gently, ‘No matter how much
I’d want to – god, I want to have you as mine in the eyes of the church, but
they wouldn’t allow it.’
‘It’s okay; we have accepted that very few monsters would willingly have us
both in wedlock.’  Sans began, holding his brothers hand – stroking it
comforting manner. Papyrus continued with a shaky smile,
‘If you love us forever and ever, that would be enough.’ Papyrus smiled gently.
‘We don’t need the church’ Sans shook his head at the thought.
‘We don’t want a ring.’ Papyrus threaded his brother fingers with his own
‘We just want you.’ They both said in unison, walking to their bed – quietly
unbuttoning their shirts and their trousers, revealing bone that the doctor has
examined well during their medical check-ups but unable to see it in a sexual
light that he is seeing now. Laying down in their nude glory, panting and
trembling a little under the doctors scrutiny – Gaster had quickly walked over
and hummed his approval, causing the brothers to flush blue and orange.
‘You truly are beautiful – unique and one of the kind.’ Gaster smiled climbing
on top of the other, pressing a skeleton kiss to both their heads only to
stumble back a little surprised when Papyrus, the more docile of the two opened
his mouth and licked Gaster’s teeth – Gaster smiled, and opened his mouth which
the inexperienced tongue explored the elders mouth; making up for it with his
excitement however.
Sans let out a low whine, watching his brother have all the fun, Gaster pulled
away at the sound of the others discontent and began another battle of tongues
with the smaller skeleton – Papyrus still recovering  from the intense first
kiss, staring a little giddy at how the doctor and his brother were connected.
Papyrus loved his brother and he was quite content to share the doctor with
him, they had only started to consider sexual relations when they had
accidently walked in on Undyne being pleasured by Alphys – the carnival girl
and the mermaid of the freak show seemed to make it work, so why couldn’t them
and the doctor?
They both had a little crush on the handsome doctor – when they were 6, Papyrus
declared that he wanted to marry the royal doctor after the other fixed up a
scratched knee – much to the doctors amusement and embarrassment – Sans only
reprimanded the other saying that the doctor had a gentle wife already. Gaster
only had a grim look and said to them with a sad smile, ‘Not anymore.’
Papyrus didn’t either want to see the sad expression on the others face – so he
made sure to always make the good doctor smile. Gaster pulled away from the
dazed smaller skeleton, a  string of blue saliva connected their mouths briefly
– Sans looked a little star stuck at the doctor, experiencing his first lovers
kiss.
Gaster smiled down at the two skeletons under him – flushing a little when Sans
began to trace his brothers ribs, Papyrus trembled and flushed at the sensation
that took over his mind; quickly returning the favour but rather moving to rub
at his brothers spine before it fused into one.
‘We touch ourselves at night, thinking about you Doctor…’ Sans began slowly.
‘Do you now…’ Gaster said, quite calmly which he was proud of.
‘Yes, we can’t help it…’ Papyrus shook his head, lamenting comically like it
was a medical problem
‘Don’t worry, that is perfectly healthy.’ Gaster finally found his voice,
smirking a little at them, ‘I did too – on your 14 birthday, you were wearing
that Harlequin costume during your performance.’
‘You watched us?’ Papyrus flushed at that, that performance had been a disaster
– one on the clowns had accidently ripped their costume revealing their bare
bones to the audience.
‘You both looked lovely – it’s a shame about the costume…’ Gaster stroked their
faces
‘What did you think about while you touched yourself…’Sans grinned a little at
the doctor, who flushed and looked at the caravan walls rather than the two
skeletons staring at him
‘I imagined I was the clown, while I ripped off your clothes – pressing you
into the ground as I had my way with you…’ Gaster said honestly, watching for
any sign of disgust or ire – but none bubbled out just the vibrant flushes that
covered their faces.
‘We had a dream where you made us seat in your lap while you had your way with
us.’ Papyrus giggled and covered his mouth, as if he told a dirty secret –
getting bolder.
‘Ah, well you two seem to have a good imagination – that is good.’ Gaster began
to kiss and lick at their bones evenly – moving down slowly till he finally
reached the join in their spine, staring at the erect penis jutting from the
pelvis and further down was a puffy, wet vagina – both seemed to be made with a
mix of blue and orange magic.
Gaster quickly pulled his waistcoat, shirt and hat off – leaving his trousers
on for the moment
He licked his teeth at the sight, pulling the other legs over his shoulders –
he briefly wondered if both would feel the same amount of pleasure, well he
would find out. He wrapped a hand around the small shaft, pressing into the
slit – the smaller skeletons arched a little in the unfamiliar feelings of
large hands caressing their virgin bodies so intimately, the doctor leaned down
into the others dripping entrance – pressing his tongue against the malleable
magic, slipping past the lips quite easily.
Papyrus and Sans moaned loudly, feeling the walls of their magic being explored
and caressed so intimately – the purple tongue continued to lick out their
honey pot and toying with the little swollen nub, making the body underneath
the doctor spasm and leg twitch on the other’s shoulders. Gaster could taste
the others magic on his tongue as he quickly thrust his magic in; his tongue
was quickly being coated with every plunge.
Gaster knew the way the others magic was beginning to clench on his tongue and
the sped up panting underneath him – Gaster continued to slurp at the others
sweetness, pressing his tongue against the others clit. The smaller skeletons
arched suddenly as he came – the twitching member was pressed and tug as
streaks of come sprayed out coating the pelvis and the spine, and the good
doctor got a mouthful of fluid too. Gaster pulled away happily swallowing the
others essence and licking away the come that dripped down his chin – Sans and
Papyrus stared dazed at the doctor whom stared at his lovers heatedly, he moved
to undo his trousers; revealing his proud purple cock much to the delight of
his love-struck lovers .
‘Boys, do you wish to go all the way?’
Sans nodded, and Papyrus followed suit – both recovering from such an intense
orgasm, neither had considered to stimulate both ectoplasmic organs at the same
time before. The doctor rearranged the others legs, spreading them for easy
access – come dribbling out of the slightly gaping entrance and the little cock
was beginning to harden once more.
Gaster nudged his cock against the others entrance, the slickness allowing his
easy access – stilling at the look of pain on the skeletons faces.
‘Tell me when you are ready to continue.’ Gaster stroked the pelvis of his
young lovers – their arms wrapping securely around him, panting desperately
against Gaster’s broader body. The bothers looked to each other and back to the
doctor nodding their consent for them to keep going. Gaster groaned as he felt
the tightness swallow his hardness – there was no way he was going to last any
longer than the two younger boys but at least he will make sure they will enjoy
 their first time.
Gaster thrusted in and out of the others tight entrance – Papyrus was staring
transfixed at where they joined and Sans was busy moving a slick hand up and
down on the cock, both creating there rhythm as Papyrus tried to meet the
others thrusts but ending up just rolling his hips against the almost constant
fullness. Saliva was dribbling down Papyrus chin as he was quickly overtaken by
the intense feeling that his brother and he shared – Papyrus and Sans drew
tight as a drawstring and the feeling of fluid swimming around his plunging
cock and the spray coating Sans’s fingers was almost too much the doctor.
The tight body seized and squeezed him tightly, but he still was thrusting into
the weeping pussy – Gaster stilled and trembled as his own member twitched
inside the other, finally finding the satisfying relief that he dreamed of. His
vivid purple cum filled the others magic, which took his offering eagerly and
making the boys moan tiredly at the sudden warmth.
Gaster panted heavily, grabbing the boys so they were on top of him but still
filled as he lay down onto the messy bed – the two skeletons looked ready to
pass out, gently rubbing at Gaster’s rib cage and pressing kisses and little
kitten like licks to his aged bones. The boys finally got comfortable on top of
the other, resting their heads on each of Gaster’s shoulder – allowing the
sandman to whisk them all to a peaceful slumber.
===============================================================================
 
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