The ponies of Equestria are unique in many ways, compared to other creatures. And one of those many ways is in relation to how their estrus cycles work.

You see, ponies go into heat like many other creatures do. For a period of three to seven days, several times a year, a mare of breeding age will become open to breeding from a stallion. Heightened libido for both the mare and any virile stallions around her, and a heightened fertility.

But there’s the thing. For ponies, their fertility is heightened during heat. They aren’t entirely infertile when not in heat. If you were to ejaculate into a mare’s pussy, there is the slightest possibility that you may end up breeding her.

It’s a slim chance. Less than one tenth of one percent. And most ponies would never have to worry about it, they can take a trip to creampie city without a care.

But, as the Cake family would learn the hard way, those chances can go up considerably if, say, your partner were to pump ten gallons of virile seed into you while plugging up your pussy so none could escape. Or if you went over a dozen rounds with them cumming inside you.

— — — —

Pumpkin Cake groaned as she waddled around Sugarcube Corner, her belly full of foals. And with that plus her already-sizable tits having grown to the size of yoga balls, her back was killing her.

“I hear Pound knocked up his mom and sister last time they went into heat,” a customer whispered to his friend. Ponies had been whispering pretty often about Pumpkin since Hearts and Hooves Day six months prior. She wasn’t sure whether the rumormongering about her pregnancy was worse, or the comments made about her breasts now that her tops could barely cover her nipples.

“I heard they had Carrot watch while he did it too,” the aforementioned friend murmured back.

Though they managed to shut up rather quickly once they caught sight of the glare Pumpkin was sending their way. She was tempted, oh so sorely tempted, to waddle right over there and set them straight that her father had been the one to knock her up, thank you very much!

…But, she quickly reined herself in when she thought about how hard it would be to raise their inbred foals from the prison, where they would inevitably be sent after she publicly confessed in front of a bakery full of witnesses.

She felt a kick in her belly, from one of her foals. They came rather often, considering the quantity of little Cakes-to-be growing inside her. The doctor had estimated quadruplets, four new additions to their family. At least.

She winced when she thought of what it would be like when it came time to give birth. But she figured she had it better off than her mother. Cup Cake had a whole dozen foals growing inside her. She'd barely been able to even get up from bed, with how large her belly had grown.

It was for that reason that Pumpkin had ventured downstairs actually, to fetch a meal for her immobile mother. Celestia knew Pumpkin wouldn’t be able to work the bakery in her current condition. Pound, Carrot and Pinkie handled most of the work around the bakery ever since the mares of the Cake family got knocked up, with some help from Button’s little sister-daughter taking on her first summer job.

“Here,” Carrot said as Pumpkin walked up to the counter, already knowing what Pumpkin had come for as he held out a plate with a hay-filled bun and some chopped carrots.

“Thanks.” Pumpkin held out her hand to accept it, but was caught off guard when she felt a wetness coming from her breasts. “Shit…” she whispered to herself. She was leaking again.

It wasn’t uncommon for a pregnant pony’s teats to leak on occasion. But it seemed like the size of Pumpkin’s massive mommy milkers had led to them producing quite a large quantity of mommy milk.

“I’ll take the meal up to your mother, dear,” Carrot said. “Pound’ll help you with the milking machine.”

Pumpkin winced. “Okay, Dad.” Truthfully, she preferred it when Carrot handled her milking. But they did have a tendency to get frisky when he did; apparently he liked sucking on her tits even more when actual milk was involved.

So with it being in the middle of the work day, it made sense for Pumpkin’s brother to be the one handling her milking. She and him were entirely unattracted to each other at the best of times. And their relationship had gotten especially tense as of late.

Carrot led Pound and Pumpkin upstairs, but whereas Carrot went on to the master bedroom, Pound and Pumpkin entered the spare room. It was set to be the bedroom for at least some of the over-a-dozen new Cake family members. But for the moment, it housed an old milking machine borrowed from the Apple Family.

Pumpkin took off her top and sat on the wooden chair they’d placed next to the machine, as Pound got it started up. Pound took the pumps and walked over to place them on Pumpkin’s nipples, but just as he was about to put them on he stopped to stare at Pumpkin’s pregnant belly for a moment, chuckling. “What?” Pumpkin asked impatiently.

“Sorry, sorry, it’s just… What are the odds, you and Mom getting pregnant, out of heat, at the same time? And with that many foals? I mean, it was you and Dad’s first time back on Hearts and Hooves Day, right? And, like, me and Mom, I’ve come inside her a billion times before and…” he caught himself and cleared his throat, placing the pumps on Pumpkin’s nipples.

There was a tense silence between the twins for minutes, the only sound in that room being the milking machine doing its thing, sucking up the milk from Pumpkin’s breasts.

“...Sorry,” Pound said.

Pumpkin turned to face her brother. “Huh?”

“I’m sorry. I thought that Dad was okay with me and Mom, I really did. I made sure to ask him, and I thought he meant it when he said he was okay. But I should’ve noticed how left out he felt.”

“And?”

Pound sighed. “And, I should’ve known it was too far to take his wife out of town for a romantic Hearts and Hooves Day getaway.”

“And…?”

Pound seemed puzzled, as though he was searching his brain for what it was Pumpkin was referring to, before cringing. “And… I should’ve known it was especially too much for me to send a photo to him of Mom after I filled her up with cum.”

Pumpkin waited a moment. “...Apology accepted. I mean. I’m not really the one you should be apologizing to. But, I believe you when you say you’re sorry.”

Pound nodded his head. “Trust me, I know I have some making up to do with Dad. I’ve been practically begging for forgiveness. He says it’s okay, but, he’s been saying it’s okay for years. I don’t know yet if he means that.”

The silence that followed was still somewhat uncomfortable, but the tension had been slightly lightened by Pound’s apology. But Pumpkin had some things to say as well. So she sighed, and prepared herself to say her part. “I get it now, y’know?”

Pound raised his head. “Get what?”

“I get it. Dad and I have been together for half a year now, and it sucks, having to hide it from everycreature in town. We have to play pretend all day, like we’re just a normal father and daughter. Even if everypony knows. Like, rumors are one thing, us being publicly openly lovey-dovey is another.

“So, I understand now. I understand why you and Mom would wanna get out of town, go where nopony knows you’re parent and child. Somewhere you can just be openly in love, and Hearts and Hooves Day is the perfect time to do that. I get it now, because I wish I could do the same with Dad.

“And, hey. If you hadn’t spent years stealing away his wife… if you hadn’t swooped her off to Manehattan on Hearts and Hooves Day…” Pumpkin took a deep breath, hoping to calm down. “I wouldn’t have had the chance to confess to Dad and spend all night making sweet, sweet love with him. So, uh. Thanks? I guess?”

Pound was silent for a few seconds longer, before shrugging. “You’re welcome? I guess?” And after a moment more, he spoke up again. “So, uh, does this mean we’re cool?”

“What do you mean?”

“Y’know, like… no more glaring at me every time Mom so much as hugs me. No more yelling at me about how I’m breaking Dad’s heart.”

Pumpkin thought for a moment before smiling. “Yeah. Sure, I guess we’re cool.”

After only another minute, Pumpkin’s milking was complete, no more milk coming from her melons. Pound removed the cups and placed them back with the machine, helping Pumpkin up to her feet. But as Pound made his way to the door, Pumpkin spoke up again. “Just promise me one thing.”

Pound turned to his sister. “Yeah?”

And Pumpkin answered with a grin. “Next Hearts and Hooves Day? Let’s make it a double date.”

Author's Note

Hope you enjoyed and/or got off to my grand return to smut writing! Apologies if I'm a bit rusty; it's been around about two and a half years since I've written proper smut with a sex scene, and I've never written incest smut. Regardless, I've been wanting to write an incestuous Valentine's story and this contest seemed like the perfect opportunity.