“Mac, what in the hay is wrong with you?” Applejack said accusingly.

Big Mac looked up from his small plate. They had decided to have a picnic out in the south field. Applejack had hoped that it would cheer him up, but it seemed to have the opposite effect.

“Whadd’ya mean?” He asked, turning to her with a confused look.

“You’ve been mopey for the past few days.” Applejack clarified. “Anything bothering you?”

There was a short pause between them as Big Mac collected his thoughts.

“Nope.” He said simply.

“C’mon Mac, ah know it’s somethin’.” She said insistently. “What’s got ya on such a downer?”

“…Well…ah………….” He said, trailing off. “Nothin’.”

Applejack growled in annoyance. Then after staring at him for a few seconds, she got up and wrapped a hoof around her brother’s shoulders.

“Hey now,” She said. “Ah know something’s bothering ya. Ah’m yer sister. If ya can’t tell me, then who else can ya tell?”

Big Mac sighed. Applejack could tell this was difficult for him. Talking always was difficult for the big red stallion. But after a few moments, he spoke.

“Ah…..it’s just………..everything…..” He said sadly.

“Whadd’ya mean?” She asked quietly.

There was another long moment of silence between them as he collected his thoughts and tried to put them into words.

“It’s just……you and yer friends are always doin’ stuff…..” He started. “Goin’ on adventures. Havin’ fun. And Ah’m just…….here……”

Applejack’s eyes widened in realization. She tried to put herself in Big Mac’s horseshoes. He spent all day, every day, working on the farm. She did her own share of work too. She worked her flank off. But she did have the welcome respite of spending time with her friends. What else did Big Mac have to do? Who else did Big Mac get to spend time with?

“Don’t get me wrong…” He continued. “Ah like mah life. Workin’ on the farm and all. It just……gets old sometimes. Ah’d like ta do somethin’ else every now and again. Ya know?”

“Gee…..ah just never thought of it like that before.” Applejack said sadly. “Ah’ve always known y’all like workin’ on the farm and ah guess I kinda took that for granted.”

Applejack looked down at the ground in shame.

“Ah’ve been a terrible sister not to notice or think about this ‘till now.” She said sadly. “Ah’m so sorry Big Mac.”

“Hey.” Big Mac said softly, lifting up her chin with a hoof. “You’ve been an excellent sister. It’s mah problem. Ah shoulda said somethin’ before now. Don’t blame yerself Applejack….”

He smiled down at her and she returned his smile with an uncertain one of her own.

“So y’all wanna come with us the next time we go on an adventure?” She asked.

“That’d be nice.” He said. “But how about we do something now. Just the two of us?”

Applejack thought for a moment.

“So do ya wanna go to Canterlot with me and meet the princesses?” She asked.

“Nope.” He said. “Ah’m not one for fancy stuff. You know that.”

“Well how about we go visit Braeburn in Appaloosa?” She suggested.

“A family get-together ain’t what ah had in mind.” He said in disappointment. “Ah wanna go somewhere fun. Ya know, do somethin’ exotic.”

“Hmmmmmm…” Applejack said, putting a hoof to her chin in thought.

“Just forget it.” Big Mac said, drooping his head in sadness. “Ah’m just havin’ an off day. Ah’m sure once ah get started bucking the apples ah’ll be fine.”

“No no no!” Applejack said quickly, getting up and putting a hoof on her brother’s chest to stop him.

“Ah have an idea!” She said proudly. “Daring Do just found some really cool ancient ruins and they’re not too far from here. She just sent Rainbow Dash a map with their location. We should go check ‘em out!”

Big Mac thought for a moment before responding.

“Ya know, that’s not a half bad idea.” He said, his voice portraying his excitement. “When can we go?”

“Well ah’ve gotta get the map from Rainbow, but that shouldn’t be too hard.” She said excitedly. “But we will have to pack some supplies. Ancient ruins can be quite dangerous.”

She hadn’t seen Big Mac smile like that for a long time.

“Okay sis.” He said, excitement in his voice.

“Now y’all just wait right here while ah go get the map from Rainbow.” She said quickly, walking towards Ponyville. “You should put all the baskets and stuff away and pack some food and water for our trip.”

With that, she was off. Big Mac hurried to put the stuff away and get their supplies for the trip. This was going to be fun!

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“So you’ve got it all?” Applejack asked.

“Eeyup.” He said.

“Water, food, a compass, map, rope, lanterns……what else are we forgetting?” She asked.

“Nothing.” He said quickly.

Applejack thought for a moment.

“Well, seeing as ah can’t think of anything else we’ll need, let’s go!” She said. “Ya did tell Granny and Apple Bloom that we were going, right?”

“Eeyup.” He said again.

“Okay then.” She said.

She took out the map she’d gotten from Rainbow Dash and studied it.

“It’s about a day’s walk from here.” She said. “We’ll have to go through the Everfree forest to get to it but once we get through the forest it should be pretty smooth sailing until we reach the ruins.”

Big Mac said nothing as his sister studied the map. He was a simple pony and knew that she knew what she was doing.

Applejack started walking towards the Everfree forest as she put the map away. Big Mac followed silently behind her.

As they approached the entrance to the forest, he couldn’t help but feel uneasy. He had always avoided going into the forest whenever possible. It was a strange place and he wanted no part of it. But if they had to go through it to reach the ruins, so be it.

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The trip through the forest had been unpleasant, but thankfully uneventful. As they came out of the forest, the sight before them was incredible. The ruins were huge. The majority of the ruins had collapsed in on themselves, but some were in remarkably good condition. What sort of ponies had built these ruins and why?

Applejack had been observing him as he took in the sight of the ruins, his mouth hung open in amazement.

“Well?” She asked, smirking. “How do ya like it?”

Big Mac looked over to her, a smile spreading across his face.

“I-it’s amazing AJ.” He said.

“Come on.” She said quickly. “Let’s go inside one.”

“Wait.” He said. “Ah need a drink.”

He took out their rapidly dwindling water supply and took a small drink.

“Careful now.” Applejack warned. “We’ve used a lot more water than ah thought we would. We’ve gotta have enough for the trip back too.”

“Eeyup.” He said quickly.

They’d be fine. They’d take a look at a few of these ruins, spend a few hours, then head back. At least, that’s what he thought…..

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It was a lot cooler inside the ruins than it was outside. Perhaps that’s why the ponies of old had built them; as shelter from the sweltering heat outside. Applejack raised her hoof as high as she could, spreading the light from one of their lanterns as far upward as it could go. This particular room was very tall. It was impossible to see all the way to the ceiling.

“This looks like the main chamber.” She said excitedly. “There are a lot of other chambers throughout the ruins that lead to rooms and other places. We might even find some treasure. If we do though, we’ll need to give it to Daring Do just in case it’s important.”

They headed into another room. Then another. And another. Big Mac was starting to get bored. There was nothing but a lot of empty rooms. However something caught his eye. The room ahead had an ornate door covered in what looked like gold.

“Hey Applejack, over here.” He said.

Applejack followed her brother as he made his way into the room with the ornate door. As soon as they got inside however, they realized the room was very small - only about 10 feet by 12 feet.

BAM

Both siblings looked back in surprise as the door to the room closed shut.

“Hey!” Applejack exclaimed, running over to the door and pushing on it with all her might. It didn’t budge.

Big Mac came over as well and helped her push against it, but it still wouldn’t budge.

“Maybe we can pull it.” He suggested. “Did you bring anything we could use to pry it with?”

Applejack quickly took off her pack and set it on the ground, looking through it frantically. Big Mac watched his sister threw the entire contents of her pack all over the place. Once it was empty she looked up at him worriedly.

“Ah’ve got nothing.” She said. “What about you?”

“AJ, y’all know that the only thing ah’m carrying is books.” He said.

“Well maybe one of ‘em can help us!” She exclaimed. “Give ‘em here!”

Big mac took off his pack and handed it to his sister. They had decided to bring several books with them just in case they had any questions about artifacts they found.

“Look at this.” Big Mac said, pointing above the door. “There’s something written up there.”

Applejack looked up. He was right. There was a sign above the door written in the old language. Unfortunately neither of them could read it.

“Lemme look this up.” She said.

Applejack flipped through page after page looking for any mention of the room or the sign above the door. Suddenly she looked up at Big Mac. All the color had drained from her face.

“What is it?” He asked. He knew from past experience that whatever it was, it was bad. He wasn’t going to like this.

“W-well….we’ve got a slight problem….” Applejack said. “According to this book, we’ve been trapped inside a magical…..breeding chamber….”

“Breeding chamber?” Big Mac asked, horrified. “What exactly does that mean?”

“Well according to this, thousands of years ago ponies engaged in…selective breeding.” She said. “Ponies weren’t given a choice who they had a foal with. They were paired up by the rulers based on their genetic traits. Unfortunately, a lot of ponies weren’t willing to mate with one another because they didn’t love each other, so these chambers were constructed in order to….force them to mate. The sign above the door says that the room has been magically sealed, and only a pregnant mare can open it.”

“WHAT?!” Big Mac asked in horror.

“It gets worse.” Applejack said. “It seems there’s only about an hour of breathable air in the chamber. If the two ponies refuse to mate, they’ll suffocate and then the chamber will be opened automatically once it detects that the ponies inside have died.”

“We’ve gotta do something!” Big Mac said frantically. “Surely there’s a way to get out besides…..you know….and dying?”

“Not according to this book.” Applejack said softly. “Ah….ah don’t think we have a choice…”

“AJ, what are ya saying?!” Big Mac asked, his voice becoming extremely high pitched.

“Ah think y’all know what ah’m saying.” Applejack said, blushing profusely.

“No.” Big Mac said firmly. “No. There’s gotta be a way to fool the magic sensor or something. We’ve just gotta think. THINK AJ!”

“By my calculations we’ve got less than 45 minutes of air left!” She said angrily. “Ah’m not happy about this any more than you are, but ah don’t wanna die either! What about Apple Bloom and Granny Smith? How would they survive without us? Neither of ‘em can run the farm.”

Hearing about their family, his features softened and he calmed down a bit.

“But AJ….yer mah sister…..” He said softly.

“Ah know Mac.” She said quietly. “But you don’t want us to die do you?”

“What are we supposed to do with a foal?” He asked. “And what will we tell everypony?”

“The truth.” Applejack said confidently. “Ah’m sure everypony will understand.”

Big Mac looked at his sister with doubt in his eyes.

“Mac, it’s up to you.” She said, putting her hoof around his neck and embracing him tightly. “Ah won’t mate with you against your will. We both need to make this decision. And ah promise, ah won’t blame you. And ah don’t want y’all to blame yourself either.”

Big Mac looked at his sister with pain in his eyes.

“Applejack……ah love you.” He said softly. “Ah’m so sorry…”

“Don’t be sorry.” She said. “It’s not yer fault.”

There was a long silence between them as he tried to come to terms with what was happening.

“Do you want to……do it…?” She asked gently.

Big Mac lowered his head in shame and nodded ever so slightly.

“It won’t be so bad.” Applejack said, trying to cheer her brother up. “Ah promise, we’ll take it slow and ah’ll make ya feel good. Now c’mere.”

Applejack used a hoof to turn her brothers head towards her. Not giving him any time to object, she brought them into a passionate kiss.

Big Mac winced as if stung as he felt his sister’s lips touch his own. But he steeled himself, using all the strength he could muster to resist pulling away and allowed her to continue.

Applejack kissed her brother with all the passion she could muster. She knew that as bad as she felt about having to do this, he felt worse. He was such a shy pony and a complete gentlecolt. She could only imagine how horrible this must be for him. So she did everything she could to be the strong sister he’d always known, hide her own feelings of shame, and make this experience as pleasurable as possible for him.

Big Mac could feel his resistance breaking down. Despite the fact that she was his sister, Applejack was a very attractive mare. And his body and instincts were responding quite positively to the young, fertile mare that was kissing him. Up until then he had allowed her to take the lead and let her do whatever she wanted to him, but he couldn’t resist any longer. He pushed his tongue into her mouth and pressed against her enthusiastically as he took the lead in the kiss.

Applejack was quite surprised when her brother reciprocated her actions. She thought it would take much longer for him to get over the fact that she was his sister. She knew however that he was likely just getting caught up in the moment and that if they stopped he would be very ashamed of himself, so she let him do whatever he wanted to her and let him take control. She was getting quite aroused from the male that was now dominating her.

Even though he was her brother, she had always thought of him as the perfect stallion. Throughout her life, she had always judged the other stallions she met against her brother, and without fail they would never measure up. If he hadn’t been her brother, she would have pursued him and she knew that she would always be a little envious of whatever mare managed to snag him. She just never thought that mare would be her.

The heat in her loins was getting unbearable. Unable to resist any longer, she reached down and started rubbing herself furiously. Her actions didn’t go unnoticed by Big Mac, who also reached down and started rubbing his cock. After several minutes, he couldn’t handle it anymore. He stopped and broke the kiss abruptly, surprising his sister as she nearly lost her balance and had to bring her hoof away from her marehood in order to avoid falling.

“Applejack, ah….” He said softly.

Applejack could tell he was really lost in the moment but still wasn’t able to shamelessly ask his sister for what he wanted. Not wanting to lose the momentum they’d gained, she quickly took the lead.

“Lay back.” She said, pushing a hoof against his chest.

Big Mac complied quickly, laying onto his back. His cock sprang up, erect and throbbing. Applejack couldn’t hide her surprise at how big he was. She hadn’t seen him fully erect since they were foals, and he had grown significantly.

Not wanting to kill the mood, she quickly got on top of her brother bringing her mouth to his cock and putting her marehood over his face. Without any hesitation at all she took his member into her mouth, sucking on it expertly.

Big Mac gasped as his member was enveloped by his sister’s maw. Not wanting to leave her hanging, he licked her slit experimentally. She jumped slightly at the sensation, but never stopped working him. Big Mac dove into his sister, bringing his muzzle into full contact with her marehood and pressing his tongue as far inside of her as he could. She moaned at the sensation, her mouth still stuffed with his cock. The vibrations from her moan sent waves of pleasure through him. As she bobbed her head up and down, he ate her out sloppily. Big Mac felt like he was close. He pulled out of her.

“Stop!” He said, louder than me meant to.

Applejack stopped in surprise and removed his member from her mouth.

“What?” She asked, somewhat upset that she had been forced to stop.

“Ah….ah can’t hold on any longer.” He said. “If we keep going ah’m gonna….”

“Oh….yeah….” She said in realization.

She had gotten totally caught up in the moment as well. She’d forgotten that he needed to come inside of her in order for her to get pregnant. Just the thought of it caused knots to form in her stomach. She’d never been pregnant before and certainly wasn’t ready for a foal - let alone getting knocked up by her brother! But she had to be strong for him. She had to hide her hesitation, her fears, and her discomfort about the situation they were in. And she could do it…for him.

Applejack got off of him and turned around so that they were face to face. When she looked at him he blushed, which made her own face heat up as well. She slid down him until she could feel his hard cock beneath her. She could feel it nestled between her leg and her thigh and could feel as it jumped every few seconds from the stimulation.

“You ready Mac?” She asked quietly.

“E-eeyup.” He said softly.

It was the most pitiful “eeyup” she’d ever heard from him, but she didn’t let that distract her. She slid up his body and felt as his member came with her. Once she was far enough above, she tried to line herself up as best as possible before pressing down. Her mark had been a bit off, but after pressing hard against her nether regions it slipped inside of her with ease. She felt as inch after inch of it slid inside of her, her walls adjusting to his large girth as it spread her open. It seemed to take forever, but finally she felt her body press against his as he was completely sheathed inside of her. She felt his large sack press up against her rear and just imagined how much cum he had in there just waiting to be let loose inside of her. Her brother was going to cum inside of her. He was going to impregnate her, and she was going to let him. Just the thought of it made her dizzy.

Big Mac had felt every inch of his sister’s tight pussy as she had taken him inside of her. He looked down between them at her pussy which was wrapped tightly around his member. It finally hit him. He was having sex with his sister. And he was surprised to realize that he didn’t care she was his sister. In fact, he had never been so aroused in his entire life. His sister was one hot mare, and he was having sex with her. His entire cock was inside her body. It pulsed every few seconds in arousal, but as he realized how hot this whole situation was, his member jumped more frequently.

Applejack could tell by how fast his cock pulsed inside of her that he was getting more aroused. She had purposefully paused after he was balls deep inside of her in order to give herself more time to absorb the situation. But there was nothing left to think about. They were having sex. She was going to let him impregnate her. And they were running out of air. She started moving slowly, lifting herself up and then sliding back down. At first she only moved about an inch each way, but after a few thrusts she was sliding multiple inches in and out of her pussy at a time.

As good as the initial penetration had felt to Big Mac, the feeling of actually fucking her was absolutely incredible. His sister’s pussy was incredibly tight, and it squeezed his member each time she pushed him inside of her again. In and out, in and out, in and out, in and out. The rhythm she had set was giving him a lot of pleasure, but he wanted to be in control. As much as he wanted to be a gentlecolt, this was the only time he’d ever get to have sex with his sister, and he was going to enjoy it as much as possible. He grabbed her and hugged her against his chest tightly, preventing her from moving.

“Big Mac…?” She asked in surprise.

Without responding he started moving his hips, sliding himself in and out of his sister. Realizing that he wanted to take control, Applejack simply laid against him and let him do what he wanted to her. As he fucked his sister, he shoved his snout into her mane and took a deep breath. He’d always loved the smell of his sister. He’d never felt right about smelling her mane before, but seeing as they were having sex he doubted she’d care.

His actions hadn’t gone unnoticed by Applejack, who blushed as she realized what he was doing. Her brother was really getting into this. He was rutting her and smelling her mane like she was just another mare that he was having sex with. It aroused her greatly. Her brother wanted HER. Even though she was his sister, he had been able to see past that. She had never really considered herself pretty before, and was quite flattered that a stallion as amazing as her brother could become so aroused by her.

“A-AJ…” He said softly.

Despite how softly he had said it, it still surprised her.

“Y-yeah?” She replied.

“Ah…Ah’m close…” He said, just as softly.

Hearing that caused Applejack’s arousal levels to shoot through the roof.

“Go ahead Big Mac.” She said, trying her best to hide her excitement and failing miserably.

Hearing the excitement in her voice made him even more eager to release. He pounded her pussy as quickly as he could, trying to get as much pleasure as possible before it hit.

“Argh!” Applejack groaned as she came.

He felt as her pussy tightened around his member and her whole body started to shake. Realizing how much pleasure he was giving his sister, he couldn’t hold back any longer. Realizing there was no turning back, he buried his face in her mane as he came.

Applejack had been trying to hold back but couldn’t any longer and cried out in pleasure as she felt her brother’s cock pump over and over, releasing copious amounts of seed deep inside of her. With each pump she could feel his member pulse inside of her. His balls contracted against her rump as they pumped his life-giving seed through his member and directly into her womb. He was squeezing her tight against him, as if he thought that if he didn’t forcefully keep her in place she would try to get away. But she couldn’t get away even if she wanted to. She laid against her brother, shaking in pleasure as he impregnated her.

She experienced the electrifying pleasure throughout her entire body as her brother claimed her. Every time his member would spurt it was like he was giving her his life force, increasing her pleasure and making her want more and more. As his member pumped less and less frequently and his balls were emptied, her pleasure died down slowly as she came off her high. Suddenly she felt as her brother’s entire body became completely limp, like something had just gone out. She hadn’t realized how his entire body had tensed up as he came inside of her. She had been too preoccupied with her own experience. As she looked down at him, she realized he was completely and totally spent. His head was resting against the chamber floor, his tongue lolled out, exhausted.

“M-Mac?...” She breathed. “Y’all okay?”

Big Mac raised his head from the ground slowly.

“Eeyup…” He said, exhausted. “How you doin’ sis?”

“Fine n’ dandy…” She said, starting to lift herself off her brother. “Now let’s see if that door –“

She was cut off mid-sentence as her brother grabbed her and held her body against his.

“N-Not yet…” He said.

Applejack complied, lying against him. She could feel as his chest rose and fell with each breath he took, raising her own body in rhythm with his breathing. They laid like that for several minutes, basking in the afterglow. Applejack was keenly aware of his erection that was still inside of her. She had to admit, it felt nice being there with her brother. But they didn’t have much time.

“Mac…ah’ve gotta go see if the door will open.” She said softly.

He stayed still for several seconds before reluctantly releasing her. She slowly lifted herself off of him and grimaced as a deluge of cum came pouring out of her thoroughly used pussy.

A few minutes ago all of that was inside her brother’s body and now it was inside of her. He had filled her full of his essence, and now she was pregnant. Or so she hoped. She felt a strange mixture of worry as she reached for the door. On one hoof she was worried that she was actually pregnant with her brother’s foal, and on the other she was worried that she WASN’T pregnant and they’d suffocate and die here in this breeding chamber. As her hoof came into contact with the door she pushed with all of her might. The door opened so easily that she nearly tripped and fell on her face.

“Whoa!” She exclaimed, trying to regain her balance.

“Y’all okay Applejack?” Big Mac asked worriedly.

She looked back at him and realized that he had already gotten up.

“Yeah.” She said quickly. “Well ah guess ah’m pregnant now, huh?”

Big Mac turned away from her quickly, a blush spreading across his face.

“Ah’m sorry Applejack…” He said softly.

“Hey!” She exclaimed. “What did ah say about y’all blaming yerself? Now you’d best stop that or ah’ll kick your rear!”

Big Mac smiled and looked at his sister again.

“So….what do we do now?” He asked.

“Let’s get back to Ponyville.” Applejack said quickly. “We’ll figure out what to do from there.”

“Eeyup.” He said.

With that they walked out of the ancient ruins and towards Ponyville. They had a lot of explaining to do…