>you're out for a stroll in the Everfree Forest
>it's a nice day, you have a saddlebag strapped around your gut, and are hauling a big load of specialty spices and herbs from Zecora
>some of the bakers back in Ponyville are having a cook-off, and needed something extra to spice things up
>that saddlebag is tighter around your belly than it should be
>Zecora let you "sample" some snacks and breads made with the spices, and only smiled and spun some rhyme about earth pony appetites when you ate the entire platter
>you're halfway to the exit
>despite almost slipping up once, you've avoided the poison joke and other hazards
>it took you months to work off the weight your last brush with poison joke gave you, after all
>you pick up the pace, sweating a bit
>the scent of the herbs and spices is overwhelming, and you worry some of the forest's residents may come looking for a snack
>you slow back down
>you're hardly a quarter mile from the exit
>you're exhausted, drenched in sweat, and about to fall over
>you aren't exactly out of shape, but that bag is heavy, the atmosphere of the forest isn't as friendly to athletics as the open air, and your overstuffed stomach is draining your energy at an alarming rate
>luckily, there's a safe haven shack nearby
>you slip inside the shack and lock the door
>thanking the Princess's safety initiatives, the reason the scant few refuges in Everfree exist, you lay down and take a nap

>morning breaks, and your empty stomach is your alarm clock
>as luck would have it, you still had a day to deliver the goods, and that overindulgence last night didn't leave any lasting effects on your body
>unfortunately, you're hungry
>starving, even
>you don't have anything for breakfast packed, and can't eat any of the spices
>you search through the shack, actually noticing what's in there this time around
>there's the bed you crashed on, a table with two chairs, a wood stove, and a cupboard
>the cupboards of these shacks were stocked every few months by some ranger ponies, and this one was overdue for a resupply
>there is hardly enough water to make a cup of tea, and even if you ate all the survival crackers, it would barely be a snack
>it can't be helped, you need the energy
>down go all the crackers and water
>you pull out a pen and mouth-write an apology on a note pad, and head out the door
>you're so close to the exit you can see ponies on the road outside
>just before you make it, a massive, purple blob jumps in front of you
>it's some sort of slime beast, you remember hearing rumors about these things
>the two ponies on the path, not 100 meters away, stop and stare
>the slime beast soaks up any droplet of itself that may have splashed on the ground
>its form shifts, turning into an exact replica of you
>well, other than the color and the fact he's made of slime
>the thing breaks its face into the smuggest, most devious grin possible
>its form shifts again
>it's still you, but it seems to be getting... fatter?
>it doesn't stop until it's easily three times as wide as it is tall, looking like a veritable barely-mobile blob
>above its fat grin, you swear there's a sudden red discoloration, like it's blushing
>your own expression shifts from worried to annoyed as you eye the ponies not too far back
>it's some fat unicorn stallion and his even fatter marefriend
>they're sitting and laughing at you, as if they're expecting something bad to happen
>you grit your teeth and prepare to use that goo creature as a launching platform and jump out of the forest
>all you manage to do is get booped by the dirt
>standing back up, you find that your hooves are stuck to the ground by none other than purple slime
>the slime pony's face contorts like it just seeded some hot mare, and it shoots a hot, sticky load into your mouth
>you don't even have time to fret about where that came from before a second shot hits you
>this time, it formed a solid bridge of slime between you and the beast
>try as you might, you can't move away
>you can't even close your mouth
>the slime beast begins to shrink, becoming thinner and thinner as huge globs of itself pass through the bridge and into your stomach
>it tastes like the best concord grape pie you've ever eaten
>you can't decide between struggling and indulging
>not like you have a choice in the matter
>you're startled by the sounds of tearing
>to your relief, you aren't exploding
>it's just the saddlebag's belt, straining and popping from one loop to the next
>wait a minute, your belly's halfway down to your knees, almost thrice as stuffed as it was last night, but you don't feel even close to full?
>the only discomfort you feel is that belt digging into your rapidly expanding belly
>you were on the third tightest belt loop, and are about to bust the whole thing open?
>something feels off, and your escape instincts kick in again
>struggle as you might, all you manage to do is tire yourself out
>your head is locked in place, so you can't exactly look around, but you can feel your body changing
>your belly doesn't feel tight at all, in fact it's soft and squishing around that belt
>your plot and barrel are getting that same feeling, to lesser extents
>even your face is feeling softer
>the slime still looks monstrously obese, but has shrunken down enough to give you an easier view of those unicorns
>they're still giggling, snacking on something or other as if you're some entertainment device
>with a loud snap, the saddlebag's belt bursts open
>your belly fwomps out, relieved
>you barely stifle a moan of relief, which the slime beast sees as an excuse to ramp up the speed
>you're exhausted, lethargic, panting for breath through your nostrils, and as far as you can tell, getting quite obese
>the slime beast looks just a hair past chubby by this point, while you can feel your belly spreading between your fore and hind legs, reaching down to your knees
>you can feel a prominent second chin growing below your maw, and your cheeks are squishing into your tired eyes
>your plot feels like it could fill a bench
>if there's any relief to be had in all this mess, you haven't suddenly changed into a mare
>unfortunately, the way you know this is feeling your stallionhood growing and pressing against  your gut
>it's not bad enough your body is being ruined while some fatsos laugh at you, this creature had to give you new fetishes too?

>the afternoon sun rides high
>the unicorns have exhausted their snacks, and are looking quite content, watching your plight from not so far
>the last little bit of slime beast has become one with you, and the slime "bridge" shoots itself into your stomach
>it's the first thing since your light breakfast that actually feels like it's been ingested
>with a flash, you find yourself right in front of the large couple
>the stallion looks like you felt just before the belt snapped, while he mare's belly was hovering scarcely an inch or two above the ground
>they probably could have teleported you to safety long ago
>she stuffs a cake into your mouth, which you don't even try to avoid, while he holds up a rather large mirror spell in front of you
>you look just like the slime beast did, maybe even bigger
>your face is surrounded by a beachball of fat
>your belly reaches the ground, spreading across it, and sticking out far enough for three ponies to stand side by side
>your plot is big enough to crush any bench it sits on
>you can still walk, with great effort
>even the saddlebags are still secure
>with another flash, you're on a wagon you didn't see before
>it groans like it's going to collapse beneath you
>the couple offer to cart you to ponyville
>they're headed there for the cook-off anyway
>they teleport themselves onto the front section of the cart, apparently too stuffed to walk the rest of the way
>the mare uses her magic to practically forcefeed you dozens of boxes of cakes
>you try to protest, but the stallion just laughs and mentions how they hated wasting food, and were too stuffed to eat any more themselves
>this is your life now
>a barely mobile blob that has no chance of getting thin again, and an appetite that will only make you grow more