Cadance broodmare TF thing

>chrysalis impregnates cadance with changeling eggs while she's down in the caves
>she painstakingly slowly begins her transformation into a changeling broodmare
>has been able to hide her new urges and has only barely started the physical transformation, when she gives birth, easily, to her changeling nymph, orgasming explosively thanks to the broodmare physiology
>shining and the princesses look on, dumbstruck
>they isolate her to try and reverse the process, but she's too far gone, in the following days despite her resistance she grows more and more aroused at the memory of that nymph being born
>she starts to touch herself, arousal wrestling disgust as she replays it
>her hair color begins to change, her fur slowly falling out, her skin hardening into chitin as her family look on
>at this point she has a harder and harder time trying to keep herself from the dungeons, her pony reservations growing frailer as the notion of her doing it again seems less and less disgusting in her brain, the mental image of her begins to shift, she has a hard time not seeing a changeling, belly swollen with eggs, always in a state of estrus, eagerly awaiting her eggs to be born, and to be fucked and pumped full once more
>she manages to hold it off for a time, convincing shining to rut her as often as possible, multiple times a day, while the rest of them still struggle for a cure
>but at this point it only works for so long, she eventually stealthily makes her way down to the dungeons
>making out the dark forms of changelings milling about as she hesitates, just looking at them as they startle, taking notice of her
>but as they realize what they are looking at their confusion turns to arousal, as they look upon a very fertile freshly turned breeder
>the pack of drones emitting breeding pheromones as she stares there momentarily daydreaming
>it doesn't take long for her to breath in a small taste of the potent chemical
>she snaps to attention, eyes wide open as she realizes what that is, as an intense warm need floods through her body as her mind takes it in and screams at her to breed
>she is barely conscious of herself opening the gate as she lets out a quiet desperate whimper watching the multiple drones become erect, their dark members sliding from their sheaths, and trying and failing to stop herself from oogling their impressive sacks, made to pump their young into a broodmare like herself
>as she sits there, the image of her pony self warring with the image of a bloated, pregnant changeling on the floor, being bred even while swollen with young and moaning lewdly, only knowing pleasure at being used, she unconsciously opens the gate
>the changelings don't need to be told what to do at this point, they know the scent that is pouring off her, and they they know what to do
>the first one circling behind her, spares no time with foreplay, only knowing he MUST breed
>cadance is snapped out of her trance by the weight of the changeling mounting her, her confusion turning to a mix of fear and eager arousal as all she can get out is a pathetic request to wait before he thrusts his thick, pulsing cock inside, sparing no time in humping away, pounding at her thick backside as her tongue lolls out hardly remembering what she was fighting it for as she instantly knows this is her purpose, getting pounded, his fat nuts impacting her rump with a wet slap with every go, the fading thoughts of shining morphing into raw images of breeding bugs as another changeling, eager to hurry along her change forces his cock into her mouth, forcing her to taste his thick masculinity, and to smell the potent breeding pheromones he exudes, worshipping his fat balls
>knowing she cant WAIT until the rest of them get to breed her as well