You are Mahogany, a tomboyish 18-year-old Earth mare with a dark-red coat and short amber mane. Your frame is mostly average, leaning only slightly on the chubbier side to give your belly a little pudge to it, a worthy sacrifice to make for the sake of cake. Luckily, you tend to be pretty casual about your appearance, not having the same interest in make-up and large wardrobes as many of your female peers.

Like, for example, your best friend, Pastel Periwinkle, a pale-blue pegasus with with a long, flowing, royal-blue mane. Tall and curvaceous, she adores pampering herself, and you don't think that, in all the years you've known her, you've ever seen her wear the same outfit twice.

How you two became so close probably seems like a mystery from the outside, but there's really no big secret to it. You met in your first year of primary school, before you fell into your individual cliques, and have been inseparable since then. You even got your cutie marks at the same time, your talent for soccer showing up when you saved what would have been the defeating goal of the season for your secondary school team, and hers in choreography, leading the cheerleader squad for the game.

The foundation of the friendship, however, was most definitely built on a love for one thing: adventure! Excitement, danger, exploration!

Yes, despite her fancy exterior, deep down Pastel had the heart of an adventurer. In fact, she seemed less perturbed whenever she snagged her dress on a bush or tripped into some mud than even yourself. You reckon it's to do with her vast wardrobe, she seems to see all her outfits as disposable once they wear out their freshness.

And it was this adventurous spirit you shared that inspired you to make the terrifying Everfree Forest your regular stomping grounds. Avoiding wild animals and traversing the thick undergrowth gave you both such an adrenaline rush, that even after vowing "never again" after being chased out by timberwolves or manticores, you'd still be back the very next month, intent on uncovering any new secrets the wood had to offer.

And it was in this forest that your destinies would be forever altered.

It would be about five years ago now, when you were both just entering your young teens. While on one of your regular excursions into the forest, you stumbled into a small copse filled with a ton of exotic plants, the likes of which you had never seen before. Shrubs with bizarre fruits, mushrooms in every hue, and the flowers... well, they were something to behold. Such a wide spectrum of shape and colour, neither of you had ever seen outside of a springtime flower shop.

While Pastel seemed entranced by the flora, you however noticed one other important feature of the small enclosed area. Hidden amongst the tree trunks, buried under leaves and moss, was a large angular shape, from which a faint light emanated. Sneaking quietly over to it, you found a thin crack on one side, the edges of which were free of foliage, allowing you to see the pony-made nature of the wooden door frame.

Peeking inside, you saw a strange, grey-striped stallion, dressed only in a loincloth, toiling away over a cauldron. Around the room, shelves were laden with all manner of equipment, vials of liquid, and most prominently, plants. It didn't take you too long to put two-and-two together; you must have been standing in this guy's garden.

You turned to beckon Pastel to stay quiet, only to see her across the copse, admiring a large, pink flower, so bright in colour that it almost appeared to glow. She wasn't looking your way, so you started to sneak quickly over to her instead.

"Wow..." she gasped, her voice hushed in awe. "This flower would look amazing with... any of my dresses!" Before you even had time to think about stopping her, she crouched down, and pinched off the bottom of the plant's stem, lifting it up from the ground.

It glowed brighter for a second, but then with an almighty PAFF, the petals exploded into dust, shooting out a cloud of spores in every direction. You both started coughing violently, clapping your hands to your mouths as the particles flew down your airways, filling your lungs.

Evidently hearing the disturbance, the grey-striped stallion burst out of his hut, glaring aggressively as he marched over to the two of you.

"What have you done, you intruding teens?! Do you have any idea what this means?!" he barked at you, grabbing you by the collar of your shirt. "Years of care, and it was almost done! And then you come in here for what, some fun?! Well, let me tell you, little miss, that you will most certainly regret this. The plant you broke, you have no clue, just what it is it's done to you."

He ran his other hand over your chest, stopping when he reached your belly, and pressing on it hard. "Your womb, young one, is what has changed. You may find the effects to be most strange. A drop of sperm, and it is done, into your oven goes the bun. And with your child, a mighty magic, I hope you shall not find too tragic. For to the father, you must then serve, for all your life, it is what you deserve."

Still holding you roughly, he shifts aside his loincloth, revealing his erect member. "Now, if I may show some insistence, it's time you became my new lab assistants!"

You struggled against him, panicking as he went to lift up your skirt, but before any harm could be done, a blur flashed by you. Pastel had leapt into the air, and dive-bombed the stallion straight in the chest. With the wind knocked out of him, he dropped you, and you scrambled away, pushing through the brambles with Pastel keeping pace in the branches above.

You didn't stop running until you had escaped the forest and were safely back into Ponyville. Only then stopping to catch your breath, you looked at each other, and your eyes grew wide.

On one side of each of your necks, there was a matching symbol. A horseshoe, with four holes in it, from each trailed a squiggly, tadpole-like tail. Your eyes locked on each others, and you nodded, telling the other that yes, they had one too.

Your mind rushed back to those words the stallion had said to you. Something about, having to serve whoever fathered your children for life, or something...

"Pastel, this could be bad. We should tell someone about this..."

"No!" Pastel cried out, then coughed, lowering her voice. "I mean, no. We can't let my parents find out that I went into the Everfree Forest. They don't mind me coming home a mess, but if they found out I put myself in danger... with you... they might never let me see you again!"

You were shocked. You had known her posh family could be somewhat strict, but this was the first you had heard about maybe never seeing her again.

"Look," Pastel continued. "Let's just forget about this whole thing. That weird guy was probably some crazy rambling hobo, nothing he said really meant anything."

"But what about these marks?" you asked.

"We'll just say they're friendship tattoos," she shrugged. "Since there's magic that can remove that kind of thing, my parents always said they'd be fine with me getting one so long as it had meaning. And what's more meaning than sharing with a friend?"

And with that, you both shrugged, and went on home, laughing about the whole incident. You resolved never to ask anyone about the marks or the flower, and hiding the symbols at school gave Pastel a great opportunity to get through her scarf backlog. She even shared a bunch with you, despite you insisting you only really needed two, woolen for winter and an ascot for summer.

So why now, you wonder, is that whole story coming back to you? As you stand in front of your mirror, tilting your head to get a better look at your neck, you find yourself considering a distinct possibility. What if the crazy guy was telling the truth?

You sigh. This must be part of becoming an adult. With college having finished up a few days ago, you're about to take your biggest ever step into maturity. And with it, comes adult possibilities.

Laughing off getting impregnated was easy when you were thirteen and innocent. Now that you're entering adulthood, serious relationships and sex are becoming a distinct possibility.

You had had a couple of boyfriends throughout secondary and college, but you never went further than kissing with any of them. And Pastel, for all her flirtatiousness, has never slept with any of her boyfriends either. Being her best friend lets you be privy to this sort of information.

But how long would that last? Should you really be going into your adulthood, being this uncertain of a possibly life-shattering curse?

This needs further examination. Consult the town's resident specialist on all things supernatural, Twilight Sparkle.

Talk to Pastel about it

Eh, just forget about it, it's no big deal

There's one sure-fire way to find out... Let's go have sex!

Eh, it's probably no big deal. Just forget about it! (Guest chapter)

Author's Note

A brief summary of how this story's gonna work:

At the bottom of each chapter, there will be a set of options. The coloured ones are hyperlinks to consequent chapters that have been written, the plain ones are unwritten chapters that are intended to eventually be written.

This set of options is not exhaustive, quite the contrary. If you think another option should be tagged onto the end of a chapter, go ahead and suggest it in the comments. I'll tack it on, and then eventually write the corresponding chapter, if it's requested enough.

That leads me on to my next point, chapter requests. As anyone who understands tree diagrams will know, this story is going to branch wider and extend taller as it goes, and every chapter will bring me two or more potential chapters to write. This means that, if I'm left to my own devices, it could be a rather long time before you see your favourite branch play out to its fullest.

So, in other words, the sooner you want to see a certain branch be written, the more you should pester me in the comments to get on that.

Curse guideline for those wanting to write a guest chapter:

When impregnated, the cutie mark of the father will appear in the centre of the horseshoe.
Once you've been bred, you will gradually become the father's slave, as the four screws appear in the horse-shoe's holes. These can each appear anywhere from immediately to a week after conception.
Birth control does not work. Condoms or abstinence are your only salvation.
The curse is contagious, and will be spread to any female you bring to orgasm.