It was a tranquil night. The sky was free from any clouds, letting the stars and the moon shining on the peaceful land of Equestria. Big Mac was sitting in the open admiring the peace of the ranch, enjoying the relaxing winds.
Yet, despite being relaxed, the muscular pony was on alert. In the last days there he and his family had noticed that during the count of the apples some were missing. Somepony had stolen some of them, probably in the heart of the night and the apple family couldn’t allow that to happen again. They planned some patrols during both day and night. Applejack would take the day, with the help of Apple bloom and Granny, Big Mac the night.
Applejack had proposed to ask for her friends to help them on the matter but in end it was decided to let them out of this matter unless the thief was something more than the Apple family could take it.
Big Mac doubted that the thief would have been that big of a threat. After all, what kind of dangerous villain would go after some apples?
Suddenly Big Mac felt a sound coming to his left, in the depth of the orchard. Without a second doubt and armed with a torch he walked into it, ready to find the source of that noise.
The farm pony was sure to be capable to take the thief on. Built by working hard on the ranch since when he could walk and lift stuff, his body was the stuff of dreams from all mares of Ponyville. Sure Bulk Biceps outclassed him on the muscle factor, but Big Mac looked much better and, most importantly, he didn’t took any steroids. One good fist and this apple-thief, whoever that one was, would get knocked down.
Big Mac was sure of himself, but the more he walked into the orchard the more he felt nervous. And felt like somepony was watching over him.
He stopped, looking around. In the middle of the apple trees it would be easy to circle around without being seen. Then he heard something. The sound of somepony sucking something juicy. Following it, he walked into a sector of the orchard less crowded with trees. And there he saw it. No, not it, her.

Sitting on the top of a branch, a bright yellow female pegasus with long pink hair, was savoring the taste of an apple. Fluttershy thought Big Mac, confused. The shy pegasus was one of the friends of his sister, why would she come and steal from them? And then he noticed something weird: the wings weren’t those of a pegasus, but ones of a bat. And her ears looked more pointy. How was that possible? Applejack had told him about that time when, to get rid of the bats that were ruining the apple family ranch, they attempted to use a spell which backfired, turning Fluttershy into some kind of vampire pony. They had managed to turn her back to normal in the end and everything seemed to go back to normality. But apparently this wasn’t true.
“What the” muttered Big Mac. Yet, despite his voice being only a whisper, it was still heard by Fluttershy. The bat-pony turned suddenly around, looking at him with narrow eye, making the muscular pony make a small jump in fear. But then her eyes widened, staring at him with an enigmatic expression. Big Mac was unsure to what to do; one part of him wanted to run to Twilight and warn her about this situation, another part of him told him to try and talk to her. Both parts had their fair points, but he couldn’t manage to focus and choose because he was too busy staring at Flutterbat body. Fluttershy was known to be one of the bustiest mare in Ponyville and even in the world. Not that the rest of her body was less jaw-dropping with long soft legs, large flank and those beautiful eyes. Because of her shy nature the yellow pegasus tried to conceal her attractive form with many clothes and bras made by Rarity to try and keep a low awareness from the ponies of Ponyville and beyond.
But tonight she was not into being humble and shy. She almost had no clothes on, with just some pants and a bra that did little to cover her enormous tits. Each of them was more than enough to cover the whole chest of Big Mac.
Slowly, Flutterbat expression turned into what could be describe into interest. Or, to be more precise, sexual attention. She licked her lips, making Big Mac shiver. And then she leaped down from the tree, going right at him. The farm pony dodged her at the last second, making her almost crash in the bushes. She got up, ruffling off the leaves and sticks, staring at the stallion yes with passion, but with also a bit of anger.

“Fluttershy, don’t you know me? It’s me, Big Mac” he said, trying to get her out of that state.

She ignored his words and step forward, making to lung at him, ripping off his shirt with her clawed hands.
The earth pony grabbed her by the arms, “Snap out of it!”. But once again his words fell on deaf ears. If seeing not-shy pegasus caught Big Mac off guards he was even less ready for what she was going to do next: she head butted.

The muscular stallion release his holds, backing away like he was in a daze, but Flutterbat had not yet finished with him. Grabbing his arms, she forced him into an hug and making her immense rack clash with the beefy chest of Big Mac; a contact that made the farmer moan in pleasure despite his best instincts telling him that this was not the best time get aroused. But he couldn’t help it.
Flutterbat pressed her breasts against Big Mac pectorals, making him feel all their generosity and softness combined with the heaviness. It was so enjoyable and yet the earth pony couldn’t help but feel that something was off by that contact.
He didn’t had time to ponder more on that, Flutterbat head butted him again.
And again.
And again.
After the third head butt she released him from her hold and pushed him away with a flex of her incredibly large breasts, making the powerfully built stallion fall to the ground like a sack of potatoes.
Despite receiving three surprisingly hard hit on his head, Big Mac didn’t felt much of a pain. Maybe it was because compared to the pleasure that it was the contact between their bodies pressed together. Or maybe it was some other magic reason. Whatever that reason may be he need it to find a way to get out of there and warn his sister, so that they may tell Twilight and the others what happened to Fluttershy.
When he finally got his full sight on he noticed the lustful stare of the yellow pegasus and noticed how she was taking off her bra and panties. Big Mac couldn’t help but admire every single curve of Flutterbat, from her long lean legs, her large flank, those slim hips that lead up there to those massive orbs that, now that hadn’t anything to stop them, looked even more impressive than before, those long beautiful hair and those eyes so big and shiny. The farmer couldn’t deny that this deadly femme in front of him looked more like a goddess than an actual pony. Heck, he already found her attractive without the need to see her in her birthday suit. Now a part of him didn’t wanted anything else but bow before her and beg like the most humble of peasant to allow her to do anything to him as long he could have the honor to feel her touch upon him. But Big Mac wasn’t a fool and, most importantly, he had been raised by Granny Smith to not let the lecherous feelings get control over him.

No, he had to fight back. But how could he get out from this situation? He didn’t wanted to hurt Fluttershy, but it was clear that she was not herself and even more clear that, whatever she wanted, she would get it, one way or another.

“Don’t make me do something I’m going to regret later” he said, trying to sound firm.

Flutterbat wasn’t impressed, and made to lunge at him. This time, rather than just dodge her attack, he circled around her and grabbed by the back. Big Mac thought it was a good idea and, probably, it would have worked better. Sure, her ass would have rubbed against his pants, teasing even more his excited male member, but it was always less distracting than those melons.

Sadly for him, Flutterbat was not easy to be submitted. She started to move savagely in his grasp and, with the help of her wings, she managed to escape. Before the farmer could do anything the vampire female flew into the air, landing on his though neck and starting to squeeze it with her long and sexy legs, cutting his breath. Quite a dangerous move, but Big Mac had learned with the fighting lessons between him and his sister Applejack to break free from such positions. Once he figured out the right place to grab and take her off his back.

And so he did. But it wasn’t as immediate as he hoped to be and Flutterbat legs grip was stronger than he expected. When he did managed to break free he found himself taking deep breaths, wasting precious seconds that he should have used to try and run away or, at least, keep an eye on her. If he did, he may have been capable to dodge her next move.

But he didn’t. Big Mac had just regained his oxygen back when Flutterbat leaped again, only mid air this time. She tied her legs around the farmer waist and, without giving him anything but a lecherous stare, she pushed her immense rack into his head, engulfing him inside of her cleavage. Big Mac released a moan of surprise and pleasure, at first too much stunned to do anything. But then he felt that, inside that warm softness that were Fluttershy boobs, he couldn’t see that much. And, more importantly, breath. He started to struggle, trying to push her off, release it from those massive mounds. But this time it seemed that his strength was being denied and every point he thought could use to break free made his hands and arms weak. His hands landed on her long smooth legs, the firm ass and her thin hips or even the very same breasts of her. By doing so he could feel his whole body starting to lose power on both upper and down side. Everywhere except his groin area. Despite his best attempts to keep calm, Big Mac could do only so much before panic started to make him do idiotic moves like muffing for air or walking around blinded in the research of somepony or something that would help him. Nothing. Soon his of breath made his already weakened legs give up, making him fall on his knees. He needed air. Flutterbat wriggle her massive breasts while making lustful whispers that, somehow, managed to reach him. He needed air. His herculean arms still searching for the right spot before they too would lost the force to stand. And finally he found it. It wasn’t a nice move but he needed air. His hands grabbed her hair and pulled with all the strength. Flutterbat screamed in anger and pain, pushing herself back. Big Mac took some breath, savoring the air which was refilling his lungs. And then he punched her. The farmer didn’t wanted to hurt her too much, but he was desperate and doubted that the vampire pony would have let him to repeat the trick. Still he didn’t put that much force into his fist, just enough to get completely free from her grasp. And it did. He got up fast, this time keeping his eyes on her. Flutterbat landed on her butt, looking hurt more emotionally than psychically, making Big Mac feel ashamed. Seconds passed and the farmer noticed that the vampire pony was still on the ground, belly on the floor, staring at him almost watery eyes.

“I’m sorry, Fluttershy” he said. He got up and offered an hand to help her get up too. And in that moment the innocent and shocked expression of the Flutterbat turned into one sly grin.

Big Mac had just noticed that that his female attacker made her next move. Using her wings to give her a great push, she delivered an uppercut to the farmer, using her knockers to knock him away and against a tree. The hit made Big Mac groggy, but it was nothing compared to what would follow. Flutterbat launched herself at him, and this time the earth pony didn’t had any time to dodge her. Her massive breasts slammed against his muscular torso, followed by a loud boing, echoed in a good portion of the apples ranch. Big Mac felt his breath being taken away just as much as his strength, while watching Flutterbat pressing her rack against him, smothering his whole torso with easy, his muscle-bound body powerless against the breasts of his female enemy. But the female vampire pegasus hadn’t finished yet. She breast pressed the farmer pectorals with so much energy he felt it actually being pushed back. And then she started rubbing them on the rest of his torso. Up and down, left and right. The pleasure that Big Mac felt was intoxicating, he could feel his male member getting more and more stiff, while the same couldn’t be said for the rest of his body. The legs were, once again, turning into gelatin and his arms were held back by his female attacker, preventing any attempts to push her back. And just when he thought that Flutterbat couldn’t make him more weak she proved him wrong. She let his arms go, using her owns to grab him by his head. And she kissed him. Big Mac felt his heart skip if not one even two beats, before starting to beat once again much more faster than before. He felt her tongue get inside his own mouth, starting to fight with his own, hot saliva dropping like a summer storm. Big Mac felt even that last bit of strength in him leave his body. With soft lips and tongue ruling his mouth, her breasts suppressing his muscles in a way that he felt them turning from solid concrete to the most malleable of clay, his arms dropped by his sides, dangling with no life in them, he was completely powerless to do anything to stop her.
After who knows much Flutterbat broke the kiss, backing a bit (but still enough to let a good portion of her breasts caress Big Mac body). With nothing to hold him up, the earth pony slides with his back against the tree, defeated. Big Mac was conscious, but he could feel how much his own body had become his prison. The pleasure that Flutterbat gave him had neutralized his self-defense.

He wondered what she was going to do next. And she toke off his pants, tore them to shreds, revealing his bulging cock. Pointy like flagpole and as hard as a mountain, Flutterbat licked her lips in anticipation while Big Mac realized what she actually wanted. Until now the farmer had thought that she was going commando on him to distract him for then plunge her fangs on his neck. But she had a different objective in mind. Knowing how powerless her victim was, the deadly femme focused on shoving his dick into her mouth and started sucking. At first Big Mac felt again an immense pleasure course through his body. As he also felt something wrong. Using the little strength that he had left he turned his eyes to look his fur and skin, noticing with horror how his color was fading, his skin turning into an ash grey. She was literally sucking both the juice and his very life out of him. And there was nothing that he could do. Except try to make the female vampire snap out of it. It was an attempt born from despair, he knew it well, but he had to try.
“Fluttershy”. Nothing from Flutterbat outside moaning of pleasure, savoring his cum, over and over again. “Fluttershy!” he tried again, louder this time. Nothing. He felt so close to the heavens door. “FLUTTERSHY!”.

Author's Note

After some months I have finally concluded the first adult rated story!
Now, there are going to be two endings, and is up to you decide which one you prefer.