I’m not too sure how I did with this one. It ended up being pretty suggestive because, well… the prompt. When I picture these two, I mostly imagine them being two assholes who are constantly trying to out-pun each other (warning though: I failed at puns in this. I’m really not good at them. I’m so sorry.)

But anyway, thank you for taking me a bit out of my comfort zone with this one anon! I hope it turned out alright!

Warning for mild nsfw and suggestive content.

---

“welcome to the bonephone, this
is sans speaking.”

Sans grinned to himself as he
heard Red whisper a muffled curse on the other end of the line. “hey asshole,
come over. the boss isn’t home.”

Sans hummed thoughtfully, chewing
on the nozzle of his ketchup bottle as he turned over, further tangling his
bedsheets. “heh, i dunno. this bed’s pretty comfy. and don’t you have work
today?” Red was silent for a beat, and Sans chuckled. “thought so. hmm, i dunno
red. i’m not sure i can support this kind of slacking off.”

Sans could practically hear Red
rolling his eyes through the phone. “just get over here, bonehead. i dunno how
long it’ll be before my bro gets back. we might not have much time… alone.”

“you still haven’t told him,
huh?”

“have you told yer brother?”

Sans was silent, before sighing
in defeat. “alright, be there in five.” Hanging up, he slowly clambered off the
bed, pulling on his shoes before heading downstairs. Excitement buzzed in his
chest, but he did his best to remain placid, knowing that Red still struggled
when it came to… affection. As he reached the door, Papyrus emerged from the
kitchen, frowning as he noticed Sans.

“SANS. WHERE ARE YOU GOING?”

Frantic, Sans scrambled for an
excuse. “uh… work?”

Papyrus’ sockets narrowed for a
moment, and Sans forced a wide grin, hand twisting on the doorknob. “I WAS
UNDER THE IMPRESSION YOU HAD THE DAY OFF TODAY, BROTHER.”

Sans froze, feeling sweat
building on his skull. “uh…”

“HOW DEDICATED OF YOU FOR TAKING
THE INITIATIVE TO PUT IN THE EXTRA HOURS! I AM PROUD OF YOU, SANS.”

Papyrus beamed, and guilt twisted
in Sans’ soul for lying to him. “heh, well, figured i’d take your advice and
put more backbone into my job, bro,” he said, scratching the back of his skull.

Papyrus regarded him for a
moment, expression dull, before sighing. “I DO NOT EVER RECALL HAVING USED
THOSE EXACT WORDS, BUT I SUPPOSE IT IS THE THOUGHT THAT COUNTS.” He shook his
head, returning to the kitchen as he called, “TAKE CARE, SANS!”

“see ya, paps,” Sans replied,
already halfway out the door. He breathed a relieved sigh as he hurried towards
the basement, ignoring the nagging part of his mind telling him it was wrong to
keep things from Papyrus. Well, the decision was only half his—he and Red still
hadn’t had a proper conversation about their… affiliation with one another.

Sans couldn’t stop himself from
pulling a face when he stepped out of the portal and into the basement of the
Underfell brothers. Though he’d visited this world many times, he wasn’t sure
he’d ever grow used to that musty smell he always tried to convince himself was
regular dust. Eager not to linger in the dingy room, he took a quick short-cut
up to Red’s bedroom, almost colliding with his darker alternate. “whoops, sorry
for rattling your bones there, bud.”

Red brushed himself off, before
grinning at Sans. “heh, ‘s no problem, i don’ bruise very easily.” He quickly
hurried to the door, shooting a glance down the passage before closing it.

Sans raised a brow bone
quizzically. “thought your bro wasn’t home?”

Red shrugged, strolling over.
“he’s not, but there’s only so much time until he notices i’m not at my sentry
station.” He grinned, looping an arm around Sans’ waist and pulling him in.
“better make this quick.”

“heh. my specialty.”

Sans smiled as Red pressed their
mouths together, his tongue immediately licking a trail over Sans’ teeth. Their
magic met, and Sans allowed his hands to glide over Red’s spine, appreciating
the shudder that ran through his counterpart as he did so. Red pulled away
briefly to smirk at Sans, before dipping his head and nipping at his sensitive
vertebrae. “y’know…” Sans murmured, taking a deep breath and letting his eyes
fall closed as Red’s tongue pressed against his neck. “you’re a real… vertebae.” Sans’ chuckles died as he suddenly
realised the implication of the thoughtless pun. Red froze against him, his
hands still clutched onto Sans’ jacket. “ah, shit, heh, well not like that, i just meant—”

“wait, quiet!” Red hissed,
pressing a hand over Sans’ mouth as he pulled away. Sans frowned, trying to pry
the hand away, but Red hushed him, eye sockets narrowing.

Suddenly, there was a shout from
downstairs. “Brother! It’s nine o’clock in the morning. Your lunch break isn’t
for another three hours. Why aren’t you at your post?”

Red winced, meeting Sans’ gaze
for only a moment, before hurriedly dragging him towards the closet, cramming
them both inside and sliding the door shut. Sans couldn’t help but grin as he
felt Red shifting awkwardly, their bodies squashed together in the small space.
“heh. never thought i’d say this, but i really hope i’m not about to get laid,”
Sans said, brushing his fingers over Red’s hip. “guess it would be kinda
fitting though, since—we’re literally in a closet.” Red scowled, slapping Sans’
hand away, before pressing his skull against the closet door.

The sound of footsteps echoed
from the passage outside, and Sans heard Red draw in a sharp breath as the
bedroom door creaked open. “Red?” Edge’s voice drifted through the closet doors,
and he muttered a silent curse, grumbling something about laziness and
incompetence. He and Red stood stock still for what felt like hours, Sans doing
his best not to breathe too loudly. It was a little difficult with Red’s hips
barely inches from his own, and one of his hands braced on Sans’ chest. At the
sound of the bedroom door finally clicking shut again, Red released a breath, twisting
to look at Sans.

“uh, maybe we should… wait a bit,
until we’re sure he’s gone.”

Sans cocked a brow bone,
regarding Red questioningly. “you that desperate for him not to know about us?
or you really just trying to get laid in the closet?”

“heh. trust me, if i get laid
anywhere, it’s gonna be on a table.” Sans chuckled quietly, but Red’s own smile
quickly faded into a grimace, and he averted his gaze. “and i… i dunno,” he
admitted, quietly. “i guess i don’t really want him ta know? ugh. why do we
have ta tell anyone anyway? it’s not their business that we’re… y’know.”

Sans shrugged. “eh, i dunno. would
make all this sneaking around a bit easier, i guess.”

Red grumbled, looking
uncomfortable. He tried to shift away from Sans, but had little success in the
cramped space. Sans grinned as Red clutched onto him for a moment to hold
himself steady. “well—yer no better,” Red pointed out, still scowling. “’s not
like yer jumpin’ up ta tell yer bro either.”

Sans hummed, nodding. “heh. guess
you’re right.” He thought for a moment, his hand idly twisting in Red’s jacket.
Eventually, he took a deep breath, mind made up. “alright. how’s this? we tell
them tonight.”

Red’s gaze shot up, eyes going
wide. “what—tonight?”

Sans gave a shrug, nodding.
“yeah. why not? it’s been a couple of months, better late than never, huh? and
anyway, i’m getting kinda tired of all these fibulas.”

Red stared at him for a moment,
deadpan, but Sans could tell he was trying not to smile. “i dunno, ye’ve been
fibuling pretty hard these past few weeks.”

Sans grinned, shaking his head.
“nah, i think you’ve been the one doing most of the boning.”

“heh, don’t sell yerself short.
you’ll femur confident about yerself if ya—”

“Oh for goodness sake, enough!”

Red and Sans barely had the
opportunity to exchange a startled glance at the sound of the third voice
before the closet door was being yanked open from the outside, the two of them
tumbling onto the floor. Red immediately scrambled to his feet, meeting his
(rather disgruntled looking) brother’s gaze with a strained grin. “oh, heh—heya
boss, how… how long were ya listenin’?”

Edge rolled his eyes callously.
“Long enough, brother.” He regarded the two skeletons with disdain. “Hiding in
the closet. How appropriate.”

Sans grinned sheepishly, shoving
his hands in his jacket’s pockets. “heh, well, looks like the truth’s come
out.”

Edge was looking very tempted to
give Sans a chastising smack across the skull, but instead, he sighed, rolling
his eyes. “The art of subtlety is truly lost on the two of you.”

Red was looking very anxious,
shifting between his feet and avoiding his brother’s gaze. “look, boss, i
uh—i’m sorry we didn’t tell ya, i just…”

Edge gave an indifferent wave of
his hand. “Spare me the apology, Red. Clearly, I’ve interrupted something.” He
smirked between the two of them, folding his arms across his chest. “I’ll give
you an hour—not that you’ll need that long, Red, nyeh heh.” Red scowled at him,
but held his silence, still looking flustered. “But I can assure you, we’ll be
having a very thorough conversation tonight,” Edge added, with a hard look in
his brother’s direction.

Sans grinned at Red, throwing an
arm around his shoulders. For a moment, Red stiffened, looking at Sans with
wide eyes. But Sans met him with a reassuring gaze, his grin still plastered
across his face. “paps and i will be there too,” he said. Red watched him for a
moment, uncertainty in his expression. “hey,” Sans said, letting affection seep
into his smile. “i promise tibia good boyfriend.”

Immediately, Sans wished he
hadn’t spoken. He and Red had never said the dreaded b word around each other. But inexplicably, this seemed to relax
Red, because his frown slowly morphed into a small smile, cherry magic
sprinkled across his cheekbones. Turning to look at his brother, he swallowed,
saying, “right. yeah. sounds good, boss.” He cleared his throat, giving Edge a
deliberate look. “uh, mind gettin’ the fuck out, now? we’ve got stuff to do.”

Edge rolled his eyes, but made
his way to the door nonetheless. “One hour, Red,” he reiterated. “I expect you
back at your post after that.”

“if he’s still walking,” Sans
said, grinning at Red. Edge pulled a disgusted face, seeming more than happy to
leave them to their devices. Only when he heard the front door close did Sans
turn to hook a hand around the back of Red’s neck. “hey red, i think i’ve
changed my mind—i really hope i’m about to get laid.”

This brought a grin to Red’s
face, and (a little roughly) he guided Sans to the bed, pinning him against the
worn mattress, his eye-lights bright. “oh trust me sweetheart—after that
performance—you’re gonna get laid pretty hard.”