>"Ah! 'Non, if'n I cum any more, Ah'll die!"
>You are Anon Jr., freshly eighteen.
>Currently balls-deep in Applejack for the fourth time in the last two hours.

>Let's retrace our steps. What sordid path did we take to seduce the silver vixen?
>(Seriously, AJ may be your mom's age, but she's smoking hot.)

>Ah, yes, that's it. You told your mom you wanted to join the Royal Guard, and she flipped her shit.
>Screaming about the risk, sparks flying from the stump of her horn...
>You'd screamed back, telling her her that she was insanely overprotective.
>Your old man had finally lost his temper. "BOTH OF YOU SHUT UP! WE ARE A FAMILY, DAMMIT, AND WE WILL NOT FIGHT LIKE THIS!"
>You could count the number of times you've seen him flip his shit that badly on one hand.
>"Fizzy, my love, you ARE worrying too much. Dial it back a bit."
>She started to say something, but Dad held up a hand.
>"Son, your mom is not being nearly as overprotective as she could be. Unlike mine - late and exceedingly unlamented bitch that she was - she hasn't prevented you from having friends, she hasn't deliberately given you bad advice, and she hasn't tried to cripple your ability to function in society so that you'd be permanently dependent on her. In short, things could be a lot worse, so back the hell down."
>You blink. That's the first time that Dad's ever talked about his mother.
>"That said, son, I don't think you're tough enough to join the Royal Guard. Applejack owes me a reasonably big favor. Let me call it in. I'll get her to let you help her on her farm and gradually make things tougher on you. That'll toughen you up and make a man out of you. After that, if you still want to join the Royal Guard, we can talk about this again."
>It was a good compromise -- it left everyone equally dissatisfied.
>You were surly right up until you and Dad took the train to Ponyville and you actually met Applejack.
>When your old man introduced you to her, you were struck dumb.
>That mane!
>Those freckles!
>DAT ASS!!!

>Still, for most of the next month, you were too exhausted from farm work to have any more lustful thoughts.
>You're in decent shape - you work out with the rest of the family, and Dad takes you hunting and fishing regularly.
>However, you were nowhere near a farmer's regimen of hard physical labor.
>Only when your body had adapted to the grueling routine did you start getting spontaneous erections again.

>It took a couple weeks for you to notice that Applejack was watching you, and quickly looking away whenever you caught her staring.
>It took another couple of weeks -and a consultation with Miss Rarity in town - before you figured out that Applejack was into you.
>You had no idea how to respond to that.
>Like both your parents, your social skills are absolutely terrible. 
>No, seriously, your mom picked your dad up in a liquor store when he was trying to drink himself to death over his failed attempts at romancing other mares.
>Since they raised you, you're about as naturally seductive as a cactus.
>Accordingly, you'd just curled up in Applejack's bed after you'd showered one night.
>She'd been so worn out that she hadn't even realized you were there.
>Until she lay down and felt you pressing up against her back.
>"S-sugarcube?!"
"I'm lonely, Applejack. And you're lonely too. I can tell. Why don't we stop being lonely...together?"
>PLEASEWORKPLEASEWORKPLEASEWORK.
>AJ made an unsettled noise. "This...this ain't right. You don't even have your cutie mark yet!"
"I'm eighteen. In my Dad's culture, that's an adult. Besides, I'm not a pony. Maybe I won't ever have a cutie mark."
>"Ah...Ah just don't think..."
"Don't think. Just feel, boss."
>You grabbed her by the haunches with both hands, flipped her over, and pressed your lips to hers.
>She froze for a moment, and you worried that you'd fucked everything up.
>Then she kissed you back, and your heart soared.

>Things got rapidly lewder from there.

>And now, here you are.
>Sweaty, pleasantly tired, but determined to finish the last round and then sleep like the dead.
>AJ's been looking increasingly worn out as the night went on.
>Apparently even Earth Pony stamina has its limits.
>"Ah! 'Non, if'n I cum any more, Ah'll die!"
"No ya won't!"
>You pick up your pace, faster and faster, until you're jackhammering Applejack.
>Your balls slap against the soaked fur at the juncture of AJ's thighs as you build towards your own orgasm.
>Applejack screams in ecstasy and clenches around you with such force that you fear for your dick's structural integrity. Her legs squeeze you so tightly that you can hear your hipbones creak under the strain.
>No mortal man could resist that orgasm!
>You groan as rope after rope bursts from your cock, splashing directly into Applejack's womb.
>Her vagina is milking your penis for every last drop of its sperm!
>AJ lifts her lips to yours in a brief, smouldering kiss, and then falls back.
>Her blond mane spreads out around her like a halo as her head hits the pillow.
>You collapse on top of her.
>It takes a moment before you realize that she's not breathing.
>HOLY SHIT, SHE'S NOT BREATHING!
>Fortunately, your parents insisted that you have a broad skill set... including CPR.
>You don't notice the blaze of light coming from your flank as you start chest compressions and rescue breathing.
>A minute's worth of frantic CPR later, Applejack gasps, and draws in a huge breath.
>"Ma? Pa? Granny Smith? Auntie Em?"
>You bury your face in her shoulder and start sobbing out apologies.
>"It's okay. It's okay, 'Non. I ain't dead. Anymore. Holy buck, ya really did buck me ta death..." AJ clumsily pats you on the back with her right hoof.
"I'm sorry, Applejack, I'm a virgin, I didn't know that could really happen..."
>The soothing gesture stops for a second.
>"Oh, Lawdy, Granny Smith's gonna come back from the dead just to tan mah hide..."
"It's okay. Dad was kind of a slut before he met Mom. He doesn't take this sort of thing as seriously as a stallion would."
>"Well, Ah do, and I bet yer ma does too! I'm gonna have to marry you and make a honest stallion out of you."
>You nuzzle your face into AJ's chest tuft.
"Well, I'm not gonna say no..."
>"At least you got your cutie mark tonight. Maybe Fizzlepop won't try an' scalp me now....oh, who am Ah kiddin'? She'll snatch me bald-headed!"
>What sort of cutie mark could you get from temporarily killing a mare with sex and then bringing her back with CPR?
>Doctor, maybe?
>You take a look at your plum-furred flank.
>Your cutie mark is Applejack's O-face.
>Buck.

***

>"HAHAHAHAHAHAHAHA!"
>Your dad's doubled over, pounding one fist against his thigh.
>"HEEHEEHEEHEEE!"
>Your mom's rolling on the floor, one hoof desperately striking the boards, horn-stump sparking.
>"T'ain't funny! Stop laughing, ya varmints!"
>Be Anon Jr.
>It turns out that the mutant offspring of an incredibly fertile magical creature and the scion of a famously fertile Earth Pony clan tend to produce lots of offspring.
>In this case, sextuplets.
>Applejack's now wider than she is tall, and she can only waddle to the bathroom and the dining room.
>And apparently your parents find it hilarious, for some reason.
>Jerks.