Fun Fact: he’s not nervous about being a dad, he’s scared of how many mood-swings his lovers will be going through.

Sunset’s the candidate most likely to win!

@ExOttoyuhr  
Another crucial tell for true alicorns: muzzle shape. Twiley’s has yet to square off Celly/Lulu/Cadance style, so that might come in as she scales up. Although after the Tirek fight, kinda doubt recognition’s much of an issue for Ponyville or the surrounding fifty miles.
 
Having recalled a Canterlot Wedding screencap pointing out background alicorns among Shiney’s Guard escort at the train stop, yet another chestnut leaps to mind: Changelings planted to (a) keep tabs on SA when duties take him away from Not-Cadance, and (b) sucker-punch the Guard within seconds of hostilities commencing. And actually, they’d still need not-alicorn Guardpones at the very least for that to work, so one theory hardly precludes the other. One wonders how often long-term infiltrators have a Derp Day(R) and manifest wings/horns the pony they replaced wasn’t born with. “Hey, Gladius, was that always there, or are ya just happy to-AWWK!”

@gorkspewdium  
I have my misgivings about that kind of thing, too. It’s a shame Twilight Sparkle and Sunset Shimmer don’t.
 
That theory of not-alicorn breeding would certainly explain the occasional background alicorn. It would also partially explain why Twilight doesn’t get much recognition: she’s still young and small enough to look like a tall not-alicorn. In a few years, when she’s Cadence-sized, she’ll be taken more seriously.

@ExOttoyuhr  
I have my misgivings as to forcing any new state of physical being upon an unwilling guardstud, but if anypone could pull the trick off it’d be those two. Or at the very least they wind up creating Flashverine(TM) by juicing him up with earthpone mojo which, as a pegasus, he can only channel to ‘grow’ lost cellular tissue.
 
Fair supposition re: alicorn breeding, though I suspect every now & again you get winged unis/horned peggies (depending on how they identify). They just wouldn’t express (enough) Earthie mojo for the full ‘Holy Trinity’ set, and might lack any remarkable mojo/physical stature.

@Poptard  
Yeah, that would be a better fit for him. It would also allow the younger Princesses to act out their emotions without having to worry about long-term consequences.

@ExOttoyuhr  
Maybe Wolverine style immortality would be good. Not just living forever, but also in his line of duty, which would often involve being the Princesses’ meatshield, which is now reusable.

@gorkspewdium  
I think you’re right – with Alicorn Rarity, you would at least know when to take cover from the approaching storm, while these two are more like lightning out of a clear sky.
 
My argument on reproduction is just the theory that alicornhood can’t breed true. On the other hand, if you had two alicorns, it probably would. Is immortality in Mr. Sentry’s future? Is it in his future whether he wants it or not?

@ExOttoyuhr  
Not that melodrama and hearing loss wouldn’t be inevitable with either St. Germain-voiced character, but at least both of The Other Purplehair’s supercharged rampages were compelled by outside-force possession (and one was technically Lulu fallout). Twiley & Shimmer, on the other hoof, need no horrific arcane influences (besides, y’know, their own brains & talents) to work themselves up into mayhem.
 
Reproduction-wise, I figure the three types have been mixing long enough post-Hearth’s Warming that ‘purebreds’ are a steadily-more-inbred minority (Exhibit A: Prince Blueblood) and there’s a lot more potential for wacky, volatile mixes than the populace likes to admit. Plus, look at Greek mythology: sure, we have Zeus & the Olympus crew, but there’s also a bazillion minor deities for every other field, stream, concept or funny-shaped rock. Admittedly a stretch, but I have my doubts that every single alicorn (or pegacorn?) need necessarily be a game-breaking superpower unto themselves.

@gorkspewdium  
… You know, you might be right on the ‘broodmares’ bit. And your archaisms were spot-on.
 
Moreover, your archaisms were slangy archaisms, which fit Luna’s impetuous, socially maladjusted, unteachable personality perfectly; I should keep in mind, when writing her, that Princess Luna probably talks like an Elizabethan fishwife, not an Elizabethan noblewoman.
 
(Speaking of impetuous, socially maladjusted, unteachable personalities, cheer up, Flash, your situation could be a whole lot worse. Twilight Sparkle and Sunset Shimmer are just paranoid, hot-tempered, magically potent, emotionally unstable potential destroyers of worlds; they’re not Luna. … Or Alicorn Rarity.)
 
 
As for this being inspired by Princess Celestia’s desire to repopulate the alicorn race… I am pretty sure alicorn reproduction doesn’t work that way, but apparently Celestia isn’t. Or else she’s willfully ignoring everything she knows about biology because she’s bored and this way is more funny.

@ExOttoyuhr  
Laid on the bullshit anachronisms thick enough, huh? And I think Lulu’s clear on the ‘broodwives’ front-not only does she have the handy excuse of adjustment to a millennium’s worth of slang-mutation, but both parties are probably zapping chunks outta the walls & howling in near-extinct Tarterian tongues whilst their doulas dive for the plate armor.
 
I’m starting to seriously wonder whether this debacle was touched off by Celly’s impatience with magic academia & friendship trials as a means of alicorn production.

@gorkspewdium  
Luna being involved in this already-over-the-top situation?! I’m literally laughing out loud over that! I do hope neither of the younger princesses heard her say “broodwives”, though.
 
Speaking of royalty, imagine what Princess Celestia would make of all this. Were it not for Twilight and Sunset inevitably doing the cutthroat-Flash-Sentry-polygamy-situation bit to themselves, she probably would’ve instigated it. As it is, I’m sure she’s merrily handing out shovels, as the two most promising alicorns in history and some random guardspony continue to dig themselves deeper into this situation…
 
Sooner or later, Twilight Sparkle and Sunset Shimmer will wake up one morning and realize, “We’re nuts.”
 
Oh, wait. They are nuts. So they totally won’t.
 
Never mind.

@ExOttoyuhr  
No sweat. Although ‘crazy’ is more/less the default state for those two, gestatin’ heirs or not. I envy Flashie not one bit in the darkly humorous off-chance that Sparkle & Shimmer start delivering simultaneously.
 
“CALLOW POLTROON! ART THOU A ROYAL GUARD OR A GARDEN SLUG?! RETURN TO THE SIDES OF THY BROODWIVES FORTHWITH, ERE I GELD THEE WITH A HALFBRICK!”
 
“Th-that’s just what THEY threatened to do, Princess!”

@gorkspewdium  
Oh, now I get it – you’re saying things will be actively uncomfortable for Flash until Twilight and Sunset are free of the pregnancy crazies. I was thinking you meant “until Twilight and/or Sunset decide to leave him alone”, which means I glossed over “the little demigod(desse)s” entirely, somehow…
 
My mistake; sorry about that.
 
Flash is definitely stuck with Twilight and Sunset for life, though. Bonus points if one of them figures out a way to make him immortal.

@ExOttoyuhr  
I was referring to the foals…unless, of course, we want two scenarios like this.

@gorkspewdium  
Make their exits? What makes you think they’re going to do that? :)

@ExOttoyuhr  
True-I keep forgetting how many forms of mindscrew come with an antidote or Undo(C) function in ponedom. However, I do anticipate plenty of burn salve for the Flashmeister when it comes time for the little demigod(desse)s to make their exits.

@gorkspewdium  
And what would life be without a little excitement? Besides, Princess Celestia knows plenty of counterspells, once she can stop giggling for long enough to use one.
 
But, seriously, Brad’s got this. I mean, they’re (possessively) cuddling him – the situation doesn’t even merit “This Will End In Tears And/Or Death” anymore!
 
 
@Background Pony #8325  
Absolutely. The question is just, will she return and emotionally blackmail Princess Celestia into helping her, or will she just happily trot through the mirror one day?

Just roll with it Flash. Some guys only get to dream about this. :p

@Poptard  
Now that you mention the mutual laxness of sanity, I recall that both have also dabbled in mindwarping. There’s a distinct possibility they’ll give Brad’s fickle butt the Stepford(TM) treatment.

Just relax and enjoy the alicorn cuddles while you can, Flash. I’m sure this slightly-unhinged formerly-evil mare along with the slightly-unhinged benevolent princess wouldn’t let anything bad happen to their husbando.

@sigh  
Bitch, please.  
She’s the only character in the whole series driven to achieve princesshood. If it weren’t for Celestia cutting off her research and a dead-end investigation into alternate worlds, she’d be six different alicorns by now.

happy ending for all!

You’re fuuuuuucked, m8.

I think the most unrealistic part of this is the thought of Sunset becoming an alicorn.