>two mares get their "fun bits" accidentally swapped after a pretty bad collision accident
>upon realizing what has happened, they refuse to be broken again right away
>maybe after they've had some time to recuperate they'll consider how to fix it, but for now, they both agree to remain like this
>obviously they settle on a gentlemare's agreement not to mess with each other, since they're both in the same predicament
>after shaking hooves and accepting profuse apologies of the ponies who helped reassemble them, they go on their way and try not to think about their new peculiarity
>several days pass by uneventfully
>there's a slightly odd sensation whenever one goes to tinkle, but they both get used to ignoring it
...
>then one evening, one of the two is laying in bed
>worn out after a long day, she absentmindedly decides to masturbate to relax a bit
>after a little bit of stroking herself with a hoof, she realizes she feels really numb... in fact she can't even feel anything pleasurable... and suddenly remembers why
>immediately stops, mortified
>goes to brush her teeth and then decides to go straight to sleep
>tries to plan to met her bitswapee as soon as possible to apologies, but she's got too much scheduled in the next few days to go over immediately
>next day is busy but goes by uneventfully, in the evening she goes straight home and to bed again
>except before she can fall asleep, she feels a hoof on HER pussy this time
>that startles her wide awake with a jolt
>but she can't deny that after not touching herself at all for several days, and then being so suddenly denied relief yesterday, she's honestly thankful for the attention
>the circumstances are beyond weird, but the stroking hoof feels nice enough that she decides to just stop caring and enjoy it
>she feels the tip of the hoof parting her lips and plunging inside, stroking the sensitive inner surface near the exit
>up and down, around and around in circles
>it moves over to her clit, and rubs that a few times
>by now she's laying back on her back, gasping and moaning loudly
>her hips are thrusting up, though of course that does nothing to press the hoof further in since her pussy isn't even on her body currently
>the other mare doesn't relent, shlicking up and down, playing with the clit, bring her closer and closer to the brink
>and then it stops
>WHY DID IT STOP
>she's SO CLOSE
>she stays frozen, gasping, waiting for the hoof to come back and finish the job
>but it never comes
>no no no no no
>she can't be doing this to her
>the realization sets in: the other mare really seems to have decided that that had been enough playtime
>and as reality sets in, so does frustration, and anger
>mind still clouded by arousal and driven by the sheer frustration of being helpless to do anything about it, she jams her own hoof down into the bits currently attached to her
>of course she can't feel anything, but her anger drives her
>in fact the lack of feeling makes it even easier, as she quickly starts rubbing hard, harder than she perhaps might have liked herself
>she flicks the clit roughly, not caring whether it could be almost painful
>her ministrations are hard and rough, as her own helplessness drives her to take out her frustration on the one keeping her from release
>tired, frustrated and aroused, she keeps going almost mindlessly, rubbing, poking, and ceaselessly stimulating the foreign pussy in an almost sadistic manner
>as one hoof gets tired, she switches it up, grinding on the other, never letting up
>it takes perhaps half an hour until she finally relents, out of breath from the effort, and with her own arousal having receded somewhat
>thoroughly worn out from the experience, she lets out a low groan of frustration at her situation before tucking in and trying her best to fall asleep
...
>be other mare
>yesterday, you were chatting with your neighbour when suddenly, you felt a hoof stimulating your nethers
>t-that uncouth mare with whom you had unfortunately suffered the private parts swap had broken the agreement you had of not touching them!
>the suddenness of the touch resulted in no small amount of embarrassment in front of your nice neighbour, and you had to excuse yourself, mortified
>at first you thought it could have been an accident, but after she didn't even bother apologizing or even telling you anything at all, you hatched a plan for revenge
>and so, come evening, once you were home and decidedly free from prying neighbors, you sat down on your couch and lowered a hoof down
>some gentle stroking, some prodding, some rubbing
>you settled into a soft rhythm, doing your best to be stimulating and pleasant
>after a few of minutes, even though you couldn't feel anything, you estimated your swapee must have gotten really worked up by this point
>you stop your efforts: better safe than sorry, even if she probably wasn't quite at the edge yet... probably
>unless she had been really pent-up
>which on second thought she might have been, if she'd really started accidentally masturbating yesterday in spite of your agreement... and maybe she was just too busy to apologize today?
>regardless, it was too late for that now, the revenge had already been exacted
>you get up and head to the kitchen to grab a late bite before bed
>halfway there, you freeze up and gasp
>now YOU are being stimulated
>and not gently, either - the other mare didn't ease in to things
>no, you feel her hoof rubbing you hard and fast
>you immediately feel yourself growing wet
>she's going at it hard, to the point where it's almost painful
>the sensations overwhelm you, and you drop on your knees, panting hard
>within a couple of minutes, you cum, hard
>as your entire body shudders from the waves of pleasure, the ministrations don't stop for a moment, and even catching your breath is a struggle after your climax
>it's not long before the second one takes you
>...
>half an hour later, you're lying collapsed in the hallway
>the soreness will probably still be there in the morning
>your throat is parched, but it takes you several minutes until you manage to pull yourself up on shaky legs
>after gulping down some water, you head back and collapse on the couch, unable to even reach the bed
>...maybe that "revenge" of yours had been a bad idea
>the next day, the first mare really knows she should make some time to head over and apologize
>but as the realization of what exactly she did sets in, she's absolutely mortified, and can't bear the embarrassment of actually talking to her swap-mate
!highlight!>how do you even start a conversation like that? "why yes I did get so sexually frustrated that I roughly abused your mare-bits for half an hour to let off some steam, my apologies!"
>...maybe tomorrow
>the other mare isn't fairing much better. "I do believe I did my best to arouse you while denying you an orgasm; whoops, sorry mate!"... maybe this conversation will be easier another day
>both mares do their best to avoid each other all day
>but then evening comes, and one mare still hasn't had any relief, while the other is still feeling slightly sore
>and both have the perfect tool for revenge directly within reach, the perfect means to torment the other as payback for what she's feeling
>and both have the perfect excuse: after all, "she started it", right?
...
>within the coming days and weeks, one totally ordinary crystal mare, not known to have any unusual sexual proclivities prior to this, acquires a strong appreciation for denial and teasing seemingly out of nowhere
>meanwhile a completely unrelated mare living in a different part of the city starts developing a truly legendary stamina
>and neither of them are particularly keen on getting smashed to pieces again any time soon