The Start of the Problems.
Bon Bon, Amber, Twink, Rusty, Starlight, Misty, Sweetheart, Patch, Bright Eyes, Clover, Melody, Teddy, Ace, Lancer, Logan Berrytown, Corny Meadowsweet, Ting-a-Ling, Dandy, Buddy, Spinner, Rosy, Kadoo, Jing-a-Ling, and Ikki Sunbright show up at the location marked on every respective letter in each respective backpack that was to be the only thing being worn concurring to the letter.
Rosy asks, "Why is every pony here?".
The other ponies answer in unison, "Got letter requesting for partner to have foal with."
Rosy realizes, "We all been tricked. I just thought that the stallion, neigh, colt that I wrought the letter to asking for an heir happened to have the same idea of wanting a foal and came up with the same idea of a location to meet at. Now I see that he copied my letter and tried to pass it off as his own to the group of ponies that were gathered together 24 years ago."
Ikki Sunbright suggests, "Since we all came here to have foals and there is exactly 12 stallions and 12 mares here, why don't we pair off to conceive the foals with the mares choosing the respective stallion that will get her pregnant?".
At first the others were going to reject the suggestion but decide to go with it as they see the point of the suggestion.
Kadoo notices, "Sweetheart, when did your Flank Symbol get an upgrade?"
Sweetheart corrects, "Actually, I got my Flank Symbols during my brief time as a nurse. The hearts on my flanks are birth marks."
Logan Berrytown questions, "So you were named for your birthmark?".
Sweetheart answers, "No. I was given my name in hopes of being 1 to care for others. If I was a stallion than I would have been named Bully."
Buddy points out, "Do your parents even know what the term bully really means?".
Sweetheart responds, "Apparently, my parents since think it has its ancient meaning as they think it means the exact same thing as sweetheart."
All the ponies stand on their back hooves to make it easier to get off their respective backpack. Suddenly they all become humanoid versions of themselves with their flank marks disappearing leaving the only features that look like flank symbols being Sweetheart's heart birth marks.
Ace screams. Melody clams him down by slapping him.
Figuring that they came this far that they may as well go through with the mating process.
Patch chooses Ikki Sunbright, Amber chooses Spinner, Bright Eyes chooses Lancer, Sweetheart chooses Dandy, Starlight chooses Ace, Bon Bon chooses Kadoo, Rosy chooses Corny Meadowsweet, Misty chooses Buddy, Clover chooses Teddy, Melody chooses Twink, and Jing-a-Ling chooses Rusty which leaves Ting-a-Ling paired up with Logan Berrytown.
Kadoo puts his penis in Bon Bon's pussy first. Logan Berrytown seeing the sight gains the courage to put his own penis in Ting-a-Ling's pussy. This sight dissolves the rest of the doubt that the others had of going through with the mating. In quick secession Rusty puts his penis in Jing-a-Ling's pussy, Dandy puts his penis in Sweetheart's pussy, Ace puts his penis in Starlight's pussy, Buddy puts his penis in Misty's pussy, Corny Meadowsweet puts his penis in Rosy's pussy, Teddy puts his penis in Clover's pussy, Spinner puts his penis in Amber's pussy, Ikki Sunbright puts his penis in Patch's pussy, Lancer puts his penis in Bright Eyes's pussy, and Twink puts his penis in Melody's pussy.
They all start fucking with only the fastest eyes seeing that they start in this order:
Clover
Ace
Ting-a-Ling
Misty
Jing-a-Ling
Buddy
Lancer
Amber
Ikki Sunbright
Kadoo
Patch
Corny Meadowsweet
Starlight
Dandy
Rusty
Melody
Rosy
Sweetheart
Spinner
Bright Eyes
Teddy
Twink
Logan Berrytown
Bon Bon
Logan Berrytown cums in Ting-a-Ling's pussy. Buddy cums in Misty's pussy. Amber cums on Spinner's penis. Clover cums on Teddy's penis. Misty cums on Buddy's penis causing some of Buddy's semen to enter her womb allowing it to get her pregnant.
Misty reveals, "Getting pregnant in this form makes you want to make out forever instead of the stop being interested that we were taught our old forms go through."
The other mating pairs decide to double up their impregnating efforts so they too can have a mother that can't get enough sex.
Starlight cums on Ace's penis. Lancer cums in Bright Eyes's pussy. Ikki Sunbright cums in Patch's pussy. Patch cums on Ikki Sunbright's penis causing some of Ikki Sunbright's semen to enter her womb allowing it to get her pregnant. Rosy cums on Corny Meadowsweet's penis. Spinner cums in Amber's pussy. Bright Eyes cums on Lancer's penis causing some of Lancer's semen to enter her womb allowing it to get her pregnant. Jing-a-Ling cums on Rusty's penis. Ting-a-Ling cums on Logan Berrytown's penis causing some of Logan Berrytown's semen to enter her womb allowing it to get her pregnant. Twink cums in Melody's pussy. Melody cums on Twink's penis causing some of Twink's semen to enter her womb allowing it to get her pregnant. Rusty cums in Jing-a-Ling's pussy. Bon Bon cums on Kadoo's penis. Ace cums in Starlight's pussy. Teddy cums in Clover's pussy. Dandy cums in Sweetheart's pussy. Kadoo cums in Bon Bon's pussy. Corny Meadowsweet cums in Rosy's pussy. And finishing the first round of cumming off with Sweetheart cumming on Dandy's penis causing Dandy's semen to enter her womb allowing it to get her pregnant.
Rosy announces, "We are going for a second round to increase the chances of impregnating us mares not aren't with foal yet."
The ponies fuck for some more time. Eventually, they feel like cumming again.
Ikki Sunbright again cums in Patch's pussy. Bon Bon again cums on Kadoo's penis but this time causing some of Kadoo's semen to enter her womb allowing it to get her pregnant. Jing-a-Ling again cums on Rusty's penis but this time causing some of Rusty's semen to enter her womb allowing it to get her pregnant. Rusty again cums in Jing-a-Ling's pussy. Clover again cums on Teddy's penis but this time causing some of Teddy's semen to enter her womb allowing it to get her pregnant. Sweetheart again cums on Dandy's penis. Buddy again cums in Misty's pussy. Patch again cums on Ikki Sunbright's penis. Rosy again cums on Corny Meadowsweet's penis but this time causing some of Corny Meadowsweet's semen to enter her womb allowing it to get her pregnant. Bright Eyes again cums on Lancer's penis. Spinner again cums in Amber's pussy. Lancer again cums in Bright Eyes's pussy. Teddy again cums in Clover's pussy. Melody again cums on Twink's penis. Twink again cums in Melody's pussy. Logan Berrytown again cums in Ting-a-Ling's pussy. Corny Meadowsweet again cums in Rosy's pussy. Amber again cums on Spinner's penis but this time causing some of Spinner's semen to enter her womb allowing it to get her pregnant.
Amber states, "Unless I miscalculated, each of us 12 mares have now been impregnating with a foal by the respective stallion that we were mating with."
Kadoo again cums in Bon Bon's pussy. Misty again cums on Buddy's penis. Starlight again cums on Ace's penis but this time causing some of Ace's semen to enter her womb allowing it to get her pregnant.
Starlight informs, "Actually, Amber, you were off by 1. I'm the twelfth mare to be impregnating in this make out session. Not you."
Ting-a-Ling again cums on Logan Berrytown's penis. Dandy again cums in Sweetheart's pussy. And finally Ace again cums in Starlight's pussy.
Bon Bon demands, "We need to stop making out now so that we don't end up in a endless make out session where we even forgo the basic necessities."
All the ponies grudgingly stop making out and pull apart. Each pony puts their respective backpack back on. As they try to return to all fours, they find out that they are struck in that form.
In the Castle of Friendship's library, Sunset Shimmer finish telling Twilight Sparkle, Applejack, Fluttershy, Rarity, Pinkamena Diane Pie, Rainbow Dash, Twilight Sparkle's royal guards, Spike, Applebloom, Scootaloo, Sweetie Belle, Shady Daze, Button Mash, and Pipsqueak about the human Applebloom's suspicions of the new pony on the Apple family farm in the Cantorlot High world as well as what appears to be a cutie mark or so on the flanks of said pony despite what world it is in.
Pipsqueak requests, "Will you allow us Cutie Mark Crusaders to do the investigation?".
Before anybody else can react: Twilight Sparkle replies, "Actually, the best bet would be to send you, Shady Daze, and Button Mash through the mirror with Sunset Shimmer and some of the more physically unique guards to do investigation as the rest of us have clear doubles on the other side even if they are of a different species."
While most in the room are upset with the decision, they understand it so are willing to go with it since there isn't any reason at this time to oppose it.
Shady Daze, Button Mash, and Pipsqueak jump in the air, slap their dominate front hooves together, than shout, "CUTIE MARK CRUSADERS INVESTIGATORS!".
Next chapter: Cutie Mark Crusaders Investigation