Prompt:
But I love Vinyl.
And I have this fantasy where I'm just pounding into Vinyl, absolutely stretching her holes, her moans are echoing through the house, and then there's a gentle knock at the door. It's Octavia. She watches silently as Vinyl screams in ecstasy before asking meekly if maybe, I could maybe sleep with her next? It's just that I've been giving Vinyl a lot of attention recently and she's still struggling to find a stallion but it's been hard and she still has needs too which Vinyl used to fill until, and then I cut her off as I cum inside her roommate and tell her that I'll consider it tomorrow, like I did yesterday. She starts to protest but Vinyl gathers enough of her mind to tell her to stop being so selfish before I spank her. Octavia says she understands and leaves the room; all three of us knowing that she's going to sadly masturbate to our loud lovemaking for the third night in a row.
And then I thank her in the morning for playing along in the fantasy.
 
Green:
>Breathe in, and out.
>In... and out.
>Relax... it’s just you, and your music, nothing else.
>Easing your grip on your bow, you guide it across the strings gently, making them sing their beautiful tune.
>The piece comes easily, your hooves work with practiced familiarity over the wooden instrument without the need for instruction.
>As you play, a noise pierces your concentration, causing you to accidentally sharp a note.
>While you quickly masque your mistake, you realize the sound was giggling, traveling down the hall.
>Frustration creeps into your mind, but you suppress it with some effort, turning your attention back to your song.
>A door slamming shut brings you completely out of your trance, making you flub another note and forcing you to pause.
>The frustration surges back, your eyes open and glare daggers at your room’s door.
>Dumb slags were probably going ta shag for the fifth fekkin time today.
>Vinyl, the minger, had been hoggin that piece a arse fer- No.
>No Octavia, you’re better than that.
>Resuming your piece, you slowly beat back the irritation in your mind.
>You are Octavia, the picture of calm, cool and collected, a gentlemare to the utmost degree. No slave to your base desir-
>”Ohhhhhh YESSS!”
>A tortured screech comes from your cello, the moan startling you and jerking your hoof, the movement ruining your solo and bringing you once again back into the world.
>You are Octavia and you are VERY horny.
>It was bad enough you were in heat, but those two tossers had kept at it like bunnies in spring for the past week as if to mock you.
>And of course, despite her usually quiet demeanor when she wasn’t partying or bothering you, Vinyl just had to be a screamer.
>Speaking of, the moaning was getting louder now, sounding through the walls like so many pieces of paper, reminding you of your need.
>Resisting the urge to hurl your instrument across the room, you robotically set aside your tools of the musical craft before they became missiles.
>”Ahh! Pull my tail!”
>Your roommate had found herself a Stallion, well maybe the more appropriate term would be male, as he wasn’t quite a pony but an alien seemingly brought here solely to rut your friend.
>This wouldn’t have been a problem if she had just been a sis and shared that cock with you.
>The two of you used to help each other all the time with your heats, so much so that you had synced up together.
>”SPANK ME! OOOH, CALL ME A BAD GIRL!”
>But no, now that the cock hungry skank had bagged her one, she greedily kept him all to herself.
>You sigh, the heat between your legs only growing with each cry that landed on your ears.
>You could do this, you were Octavia. No silly estrus could-
>”POUND MY PERFECT LITTLE PONY PUSSY!”
>You feel yourself wink against your seat.
>Buck.
>You knew from experience that masturbating didn’t help anything. It would only delay the problem, not solve it.
>What you needed was DICK, more specifically the hot, gooey spunk within to cool the raging inferno inside you.
>Vinyl was getting her share, being filled up to bursting every day while you were left by the wayside, without even a drop.
>Groaning in irritation, just thinking about your desires had swelled you up, causing you to begin dripping on the floor.
>”YES! JUST LIKE THAT, JUST. LIKE. THAAAAT!”
>You know what? You have needs too. If those two were going to live here then you weren’t to be ignored like some old spinster.
>Rising from your spot, you confidently marched to your door and threw it open.
>The removal of the barrier however allowed more lewd sounds to grace your ears, your face blooming into a blush as you winked again.
>Undeterred, you continue onward down the hall, only slightly aware of the mess you were trailing behind you.
>Reaching the eighth note adorned door, you give the portal a few raps with your hoof.
>When your only answer was more moaning, you huffed and indignantly let yourself in.
>As you crack the door open, the sight before you stops you in your tracks, leaving the door only ajar.
>All the fire in your body was replaced with a different one, spreading from your nethers throughout your body.
>When you had opened the door, you had been treated with a pleasant muskiness that made your head swim, and an extremely lewd display.
>Before you was your roommate, eyes crossed and tongue lolled as she got her brains scrambled by the absolute /rutting/ she was receiving.
>You wouldn’t have known if she was even conscious if it weren’t for the ear shattering noises being forced out of her.
>She wasn’t so much having sex as she was being /used/.
>She was on her back, hooves splayed and body limp, lurching from each thrust, bouncing against the great force being pounded into her.
>A pair of paws were wrapped around her wide hips and belly, holding onto her and keeping her from falling off the edge of the bed.
>Trailing your gaze up, you follow those paws to a strange body and further up to a head looking right at you.
>You hadn’t even noticed you were touching yourself until your eyes met his, freezing you in place.
>You try to think of something to say, but your mind is blank, the only sound coming out of your gaping mouth silenced by Vinyl’s pleasure. 
>Not slowing down in the slightest, the hooman kept pistoning into your friend, simply cocking an eyebrow in an unspoken question.
>Gathering yourself, you remove your hoof from your weeping, rapidly winking slit and formulate some kind of response.
>Foalishly, you try to talk over the shrieking mare again, your words drowned out entirely.
>Seeing as how he couldn’t have possibly heard you, you gather what was left of your courage and bashfully enter the room.
>As you get closer, you pin your ears back as the yells were beginning to be painful.
>Approaching Vinyl, you take a hoof and jam it into her noisemaker, somewhat muffling her.
>You realize too late however, that it was the one you were using on yourself, the slick juices being lapped up by the gagged pony reflexively.
>As you stand there stuttering, you were also keenly aware of the new sounds in the room.
>It was definitely worse now. The wet slapping and squelching turning you on even further as Vinyl screamed into your hoof, drool dripping around where you had gagged her.
>”What.”
>The single word cuts through you like a knife, bringing your attention back to the beast tearing apart his prey.
>You take a shuddering breath, steading yourself before answering.
“I-I was wondering if you’d consider- after Vinyl of course- umm, m-maybe possibly giving me the same treatment?”
>You tinge the last part of your words with a bit of hopefulness that came over you.
>”You want a fucking.”
>This was not spoken as a question.
“Y-yes please. You see, as you know I am also i-in heat and I’m between stallions right now which normally wouldn’t be a problem but Vinyl’s been o-occupied as of late and hasn’t had the time to-“
>You’re cut off by a grunt, Anon’s hips locking forward into Vinyl who if you weren’t currently muting, would have shattered your eardrums with the scream she was letting out.
>Oh Celestia he was cumming, you realize. Your eyes widening as you see Vinyl’s fluttering and rolling back into her head in ecstasy.
>”I’ll think about it tomorrow.”
>Those words feel like a bucket of ice was dropped over you, almost making you tear up.
“B-but that’s what you said yesterday!” You cry, not able to keep the whining neediness out of your voice.
>Coming to, Vinyl uncrosses her bright red eyes and gives you a disapproving look, spitting out your hoof.
>”Stop being so greedy Tavi, remember, he’s /my/ coltfriend.”
>As if to enforce this statement, Anon lifts up her rear and plants a loud spank right on her rump, making her let out yet another pleasured moan right in your face.
“Y-yes of course, how rude of me.”
>Without another word, you turn around and make for the exit, not caring that your shame was on full display, tail flagging in the stuffy air.
>”Wait a minute.”
>With speed you didn’t think you possessed, you whirl around to look back at gorgeous, generous Vinyl. Filled with joy and excitement that she decided to shar-
>”Who told you you could come in here?”
>Your delight was swiftly replaced with cool numbness.
“I- w-well, no one.”
>”This is my room Tavi.”
“Y-yes?”
>”I don’t remember inviting you in.”
>Uncertainly shifting on your hooves you watch as Vinyl swings her messy rear over to the edge of the bed, displaying her dripping marehood for you to see.
“You didn’t.”
>”Then I think you deserve some punishment. Clean me.”
“W-what?”
>Not responding, the white mare spreads her legs, presenting herself to you fully.
>Without warning, her horn lights up and you feel her magic grasp the back of your head, pulling you into her.
>Your lips meet hers with a squelch, the fluids there smearing across your muzzle, staining your coat.
>”Get to work.”
>Tentatively, you stick your tongue against her folds and drag it up, collecting the combined juices there and bringing them into your mouth.
>”There ya go, you’re a natural.”
>Encouraged by her praise, you continue on, lapping at the mess and sucking her clit clean earning you a moan.
>Not stopping there, you probe her entrance and scoop out as much cum as you could, maybe if you did a good enough job, she’d let you have a turn with Anon.
>Finishing her pussy, you focus on her rear next, licking at her seeping ponut expertly.
>Forcing your tongue past her tight ring, you copy what you did before and take as much cream out of it as your muscle could reach.
>Giving her crotch one last lick, you bring your head out from the musky area and give Vinyl a pleading look.
>Feeling magic prickle on your head again, you’re forced into one of her sodden thighs.
>”You missed a spot.”
>Cursing your mistake, you attempt to make up for it by giving Vinyl’s legs a tongue bath, making doubly sure you missed not even one drop for fear of being punished further.
>Absolutely sure you were done this time, you look to Vinyl for approval.
>”Great job Tavi, now, what do you say?”
>Confused for a moment, you quickly realize what she meant.
“T-thank you.”
>”Good girl.”
>That one came from the surprisingly quiet Anon who had been watching from the bed.
>Vinyl rolls over and stretches her legs grunting a little from the exertion.
>”You’re going to get ‘non ready again, then you can leave.”
“L-leave?”
>”Yeah, leave.”
“B-b-but-“
>”I think I’m giving you enough letting you taste him, no? You wouldn’t be getting greedy again, would you Octy?”
“I- No! Absolutely not, I wouldn’t even think about it!”
>Rising from the bed, Anon walks over to you.
“Good.”
>Resisting the urge to back away from his imposing frame, you sit down on the floor, ignoring the wet noise your butt makes against the carpet.
>He keeps coming, up until he mashes his stallionhood against your face, smearing even more fluids across your snout.
>Not needing further instructions, you bring his soft member into your mouth and tend to it.
>Swirling circles around the head and shaft, you feel it swell into you further, eventually encroaching on the entrance to your throat.
>Easing off of him, you get ready to move on to his orbs before his paws grab the sides of your head.
>Looking up in confusion, your only answer is him forcing himself into your throat.
>Gagging, you try to push off of him to get some air but as you’re brought off his rod, you’re quickly shoved back down again.
>Seemingly indifferent to your plight, Anon instead quickens his pace, pushing further and further into you each time.
>Gagging again, tears sting your eyes as they’re forced out from the rough treatment you were receiving, your air supply running low.
>Eventually, his hips come up to slap against your cheeks, fully burying himself inside your throat.
>Your vision darkens around the edges as you swallow and choke on his cock, lungs desperate for air.
>Then, miraculously, he lets go. Letting you fall off of him allowing you to cough up spit and gasp for life giving oxygen.
>Blinking the tears away, you look to where he was to see him lining himself back up against Vinyl, both completely unaware of your presence.
>As the first thrusts begin again, you shakily stand up and leave the room, shutting the door behind you as Vinyl’s moans once again grace the house.
>You don’t go far though, pressing your ear against the door as they continue their loud lovemaking without you, a hoof snaking its way back to the raging kiln between your legs.
>Your hoof works madly against your rapidly winking clit, every rub and tug bringing you closer to temporary relief.
>Vinyl was getting back into it now, her shrieking passing through the walls easily once more. 
>You can still taste them, their tart and salty remains lingering in your mouth and bruised throat.
>Savor it Octavia, it’s all you’ll get for now.
>You couldn’t wait for your own turn, whenever that would be, to be screwed mercilessly and filled up to the brim with his hot see- you were doing it again.
>You just don’t learn do you? You are selfish, she was right. He wasn’t yours and you were overstepping once more.
>What had happened in her room was a courtesy, you could have been ignored or kicked out but they decided to take pity on you in your state.
>And this is how you repay them, by fantasizing about replacing Vinyl in her own bed.
>You’re disgusting, how could you do that to her?
>Just listening into their lovemaking was already a gross breach of privacy, but you had to go further didn’t you?
>You’re a bad pony. You’re a bad friend.
>Seizing up, your rear legs spasm as you cum, your release gushing down them as you join Vinyl’s cries with one of your own.
“I’M SORRYYYY!”
>Leaning against the door heavily, you gather your breathing to stabilize yourself.
>Just like you predicted, you still felt the licking flames inside you. Not satisfied with a mere wank, you knew they’d be back in full force soon.
>Bringing yourself up off the door, you shamefully shuffle down to your empty room, trying your best not to eavesdrop further on your friend.
 
-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-
Good end
>Trotting down the hallway, you follow the delicious smells coming from the kitchen.
>You were once again a much more refreshed, and rested Octavia Melody.
>Rounding the corner into the kitchen, you spot Anonymous working the stove in a cute apron and Vinyl resting on her side on the floor.
“Good morning you two~”
>”TAVI!”
>Shooting up from her spot, Vinyl gallops over to you and starts planting kisses everywhere she could reach.
>”I was SO /mean/!”
“Mmm, you were great love.” You reassure the clingy mare, patting her on the back.
>”Yeah she was.” Comes the cheeky baritone of Anon.
>”I donno if I was great, I didn’t really do much ‘cept get /bucked/.“
>”I mean, look what he did to my poor booty Tavi! I can’t even sit down!”
>Your roommate spins around, almost knocking you over as she shoves her bruised tush into your face.
>You are taken aback by the sudden plot in your nose, but you feel empathy for her as you run your hoof gingerly over her red and welted skin, the damage sticking out prominently against her white fur.
“Oh dear, he was rather rough with you wasn’t he? The brute.”
>”Hey I didn’t do anything she didn’t beg me to do.”
>”Plus, if she didn’t want me to treat her that way, she shouldn’t be walking around with all that ass.”
>”Meanie.” Vinyl huffs.
>Anon turns around, and gives you a concerned look.
>”Speaking of being rough, how are you? I wasn’t exactly gentle with you last night.”
“I’m perfectly fine Anonymous, thank you. Your performance was most enjoyable.”
>”You make it sound like I sang you a sonnet and not how I actually brutally facefucked you till you almost passed out.”
“Hmm, yes well, if you are still concerned with my well being, I can show you how sturdy we earth ponies truly are. We don’t bruise as easily as unicorns do.” You say, sharing a smirk with Vinyl.