So…
Moonbutt magics up Dave and turns him into a magical uni-colt, because she just rolls all freaky like that. And then she’s like, “We hast not shipped Trixie yet. We shippeth Trixie with the OC known as Rough Draft, and they shall be the parents of this newly minted underage pony who we shall not be making things weird with before they have graduated elementary school.”
So he newly created, not totally weird and legally coerced family gets on the transition express to Canterlot where the next part of this story starts off. And Dave is like, “Can my pony-name just be ‘Silver Lining’? That way I have a pony name, but I don’t have to be poked all the time to be reminded I have a new name?”
And everypony’s like, “Sure, why not? It’s not like it’s gonna make things any weirder.”
And of course, The Great and Homeless Trixie doesn’t have a place to live. Which would have been a neat thing for Princess Moons-the-World to look into, you know, before she shipped her with a hermit OC she’d never met, and put them in charge of an emotionally damaged, age regressed former human. But it works out, because one of Trixie’s Great and Powerful is, not surprisingly, kissing up to rich ponies.
So they go visit everyone’s favorite rich-bitch ponies, Fancy Pantless, and Fleur de Laid. And then Trixie does what she does best, and puts on a self aggrandizing magic show and lets Fleur totally molest Silver, right there in front of everypony. And Fancy Pants gives them one of his smaller mansions to live with. I assume to keep the family quiet about his wife molesting an underage pony right there in front of everyone… like five minutes ago.
Meanwhile, Celestia’s giving Luna “the look” and Moonbutt knows what she did.
And Sunbutt’s like, “Dammit, Sis. First the dream-spying on the CMC, now this? Do we need to put you on a watchlist?”
And Moonbooty’s all, “It’s not like that! I totally saved him from being drawn into a foul herd of debauchery by an insane mare who immediately turned him into a pony!”
And Sunbutt just keeps giving her “the look”. Because, srsly?
And so Drafty and Trixie enroll Silver not-a-child in pony elementary school. Because nopony can think of any better plan on how to deal with a potentially unstable adult in human in the body of a pony child. Because “friendship”.
So Silver goes to “Sappy Smiles Elementary” where he meets all the friends you never got back in touch with from grade School. The Pretty Filly. The Athletic Colt. That Filly you think might be a love interest, but it never goes anywhere. And most importantly the sexually repressed bully who’s *really* too old to be in that class.
And because it’s Equestria and the bully’s family hated him enough to doom him to a destiny of a pitiable antagonist, his Name is Rough Tumble. If you know that pony naming is going to pretty much dictate your child’s entire destiny, why? Only bad ponies would name their son that.
So Big Gay Tumbler pick a fight with Silver Insert, because he’s kinda stupid. And he immediately gets his ass handed to him, because ponies fall into three categories: Good Ponies, Bad Ponies, and Total Pussies. And since most ponies are Total Pussies, bad ponies can pretty much run all over anypony till math says they run into a Good Ponie, or sometimes tougher Bad Pony. And Big Gay Tumbler is really bad at math.
And Tumbler gets his flank kicked and Sunbutt calls Silver to the Royal Principal's Office. And she looks that little mixed-up, not-a-pony, and she’s says, “Well you just beat the shit out of the school bully, so you're not a Total Pussy. That means you’re either a Good Pony or a Bad Pony…”
Then the Princess of Exposition proceeds to interrogate Silver, but she’s really nice about it, and I’m pretty sure there was cake. And Luna’s kinda defensive, because she know’s she’s on the edge of being put on “that” list, but in the end Sunbutt decides that Silver is a Good Pony, mostly because this is weird enough as it is and she *really* doesn’t want to put her sister on a watchlist.
Well, it turns out Silver beat that bad straight offa Big Gay Tumbler, and now he’s a Total Pussy. But he’s not quite ready to give up his Bad Pony status yet, so he immediately shows what a Total Pussy he is, by bringing along his adult unicorn “mare-friend”, Carrot Bottom (because having one of those totally proves your not gay right?) to hold Silver down while he slaps him around, because that’s not weird at all right? Yes, Tumbler, a high school aged colt, is enlisting his marefriend, Carrot Bottom, a grown ass mare, to aid him in restraining and dominating a grade school student. It’s exactly what it sounds like.
So Silver show’s Big Gay Tumbler what a bitch he really is, and Tumbler’s like, “I don’t wanna be a Little Bitch! I wanna be a Good Pony!”
And Silver’s like, “Dude, it’s okay to be gay. Just stop acting out violent repression fantasies and hiding behind pervy adult figure.”
And Big Gay Tumbler’s like “Wow I’m a terrible person with worse parents. But I don’t have to be cock holster for some pervy grown-ass dominatrix when it’s way less weird to just be gay!”
And Carrot Bottom see’s this and she like, “Wow, a grade school colt taking charge like that really revs my engine.”
So she tie’s up Silver for sexy domination games by easily overpowering him, which she can do because she is clearly an adult, and Silver clearly is not. And sure he’s age regressed, and actually an adult human, but Carrot Plate didn’t know that, and… ewww… But luckily before Carrot Flank can have her way, Rough Draft bursts in and calls the cops.
Because seriously, that’s what happened… in a nutshell… more or less...