The air was frigid that morning in Ponyville. It was five in the morning on February 14th. For humans it was Valentine’s Day, and for ponies, it was Hearts and Hooves Day. Almost everypony had found a special somepony for this year’s observation of the holiday.

Big Macintosh was one of the few exceptions to that. For years, he’d simply been indifferent to the whole event, except for a very memorable incident involving him, Cheerilee, a love poison and the Cutie Mark Crusaders.

This year was different, or at least he wanted it to be. On the exterior he seemed a simple and sturdy stallion, but in truth he was one of the smarter earth ponies in town. He had a lurking suspicion that the love poison used on him might still reside in his system, because he still had a mild infatuation with Cheerilee.

And just as his strength made one peg him for a simpleton, his stoic silence made him seem slightly scatterbrained. In fact, he had a tendency to do things methodically, to plan and make lists. Not to the degree that Twilight Sparkle did, but to an appreciable extent.

His awkward experience with Cheerilee made him wary of asking her to be his special somepony, but he was quickly running out of mares he found appealing in both physical and other ways. First he asked several mares who worked the marketplace, his blushes hidden by his crimson coat, and been turned down by each. Then he’d asked the charmingly tomcoltish Rainbow Dash, and been declined, as she ruefully claimed to have an absentee coltfriend. Asking the quiet, sweet Fluttershy yielded a similar result, and a similar expression. Big Mac was suspicious of whether the rumors about the two of them were true, given their eerily similar, almost choreographed reactions.

That left two mares on his list. Twilight Sparkle, and Cheerilee. Given his inclination to not ask the latter on account of the previous Hearts and Hooves Day unless he had no other choice, the former was his last shot at avoiding awkwardness.
So he approached Golden Oaks Library, where the bookish mare resided.

***

Shortly upon returning to Ponyville four months prior, Twilight Sparkle looked up the date of the two days Mark had mentioned. “Christmas” coincided with Hearth’s Warming Day, and “Valentine’s Day” with Hearts and Hooves Day. Another cultural similarity courtesy of Star-Swirl the Bearded.

As she learned this, she found out from Fluttershy and Rainbow Dash that Jason and Ethan had made identical vows. And for the three of them, that was the loneliest Hearth’s Warming they’d ever had, despite the presents and friends and family.

So they shifted their hopes to Hearts and Hooves Day. But the night before that holiday, none of them had heard from the SPARTANs.

When Twilight heard a knock on the door at an obscenely early time, she teleported from her bed to her mirror, brushed her mane and tail, and then teleported again to the front door, giddy with anticipation and with a smile that would make Pinkie Pie proud.

Still, she was tired, and when she opened the door to see a nervous Big Macintosh hoofing the ground it showed through.

“Oh! Ah’m sorry, Ah forgot ya don’t wake up at the same time as mah family. Not everypony’s a farmer, Ah guess,” He chuckled nervously.

“No, it’s fine,” Twilight answered, yawning. “What can I do for you, Big Macintosh?”

He perked up a bit when she used his name, as though that were an accomplishment. “Ah was just wonderin’ if ya had a special somepony for Hearts and Hooves Day. Oh, an’ ‘fore Ah forget, Ah brought ya somethin’.” He pulled out a heavily-worn doll from his saddlebag, and her pupils grew to fill her eyes in response.

She seized the doll with her magic and brought it close. “My Smarty-Pants doll!” She exclaimed, hugging the object tightly. Her enthusiasm turned to confusion. “Wait, why did you have her in the first place?”

“Um… Remember that spell ya used on it a bit more’n a year back?”

“Oh, right…” She blushed and lowered her ears, her eyes pointed at the ground in a mixture of shame and embarrassment. She returned to looking at him after a moment. “Thank you, Big Mac, but I’m already waiting on somebody. I’m sorry.”

The red stallion concealed his disappointment behind a false grin and nodded before trotting off.

As she shut the door Twilight sighed and headed back to her room, careful not to wake Spike. The wind outside seemed to blow it back open, so she shut it again with her magic, this time more firmly. Up the stairs and around a corner, she opened the door to her bedroom.

She wanted to wait for Mark, to see when his aircraft landed nearby, so he and his team could fill the emptiness in the hearts of Twilight and her friends. She tied a pale scarf around her neck to protect it from the cold and wind-chill, and headed out to her balcony.

The wood had been reinforced by several spells to make it much more durable and sturdy. A small metal plaque indicated the maximum capacity and load-bearing ability of the platform, as per a town ordinance that had been passed after the Mare-Do-Well incident and the accompanying spate of building collapses.

After her reinforcement spells, it could hold no less than three tons without much strain, though it was unlikely that enough ponies would ever be on it at one time to approach that limit.

There on the balcony, she rested her forelegs on the smooth oaken guardrail and stared at the sunrise. The wind tousled her mane somewhat and made her scarf flap. She could see her breath in the cold winter air.

Twilight felt a change in pressure on the wood beneath her hind hooves, betraying the presence of a visitor. She shifted her stance and looked behind her to see that Mark was standing a couple yards back, his helmet attached to his waist. He looked cleaner, his hair trimmed to a uniform buzz-cut just long enough to retain its color and his beard shaven off. He smiled gently at her, and she returned the gesture, her eyelids lowered slightly to keep the sun’s glare from obscuring her vision.

He strode over to her and rested a hand on her shoulder. “I missed you,” He whispered.

***

Fluttershy was cleaning a few of her indoor birdhouses when she heard a knock on her door. It was a heavy knock, which alarmed her. Still, she felt obligated to answer it, and so she cantered over to the entrance and opened it.

“Jason!”

She flew up and hugged him, nuzzling his neck before he could even return the hug. Seconds after he did, they both stopped and blushed. Fortunately for Jason, he was wearing his helmet, so she didn’t see that he was just as embarrassed. Then again, that might’ve made her more embarrassed.

“Oh my goodness, I’m sorry, I-I just haven’t seen you in so long, and- And you’re a really good friend…”

“I-It’s fine, really,” He stuttered.

Fluttershy hovered awkwardly for a few moments before motioning for him to come inside. He already knew that her furniture could support his weight even when his armor was on, since it was built from a highly sturdy wood found only in the Everfree Forest.

The soldier sat down on his hostess’ couch and set down a duffel bag he’d been carrying. He removed his helmet and set it atop the bag. “I brought some fatigues to change into, but I need someplace to change.”

“Oh, um…” Fluttershy blushed at the suggestion. “There’s um, a bathroom upstairs you can use.”

After he changed, the two of them spent the day curled up inside, sharing a blanket, and eating popcorn while watching movies. Outside it began to rain, worsening the already frigid temperature, and lessening the effect of the tree’s natural insulation.

By the time their fifth movie ended, night had freshly fallen. With Luna’s moon now above them, they turned off the television set and talked. They talked for hours, and that was just fine with them.

***

For Rainbow Dash, the anxiety leading up to Hearts and Hooves Day had been bearable, if only because of her well-known ability to sleep anywhere and anytime. When she was feeling down and nopony was there to cheer her up, she’d sleep through it. It was that simple.

Still, Hearth’s Warming Eve and Day had been exceptionally lonely, and having been out of contact with Ethan for months was difficult for her, just as it was for Twilight and Fluttershy.

A few months earlier at the spa, they’d met with Applejack, Rarity, and Pinkie Pie for one of their sessions. The spa was one of the only places they could relax and talk to each other in full privacy and comfort.

No stress, no judgment, just friends.

***

“So uh, Dash?” Applejack asked. “When you an’ Ethan were havin’ that meetin’ in the stable a week ago, what did y’all talk about?”

“I asked him how he dealt with the war and death and stuff. He said…” She sighed.

“Go on, darling,” Rarity goaded her.

“He said it was because it was almost all he’d ever known. He said that all the SPARTAN-IIIs were orphaned by the Covenant between the ages of three and seven. The UNSC kidnapped a few hundred of ‘em for the second class, and he was one of ‘em. They’re used to being seen and treated as mindless soldiers by humanity, so it was weird to him when we treated them, well, nice.”

Pinkie’s mane deflated almost instantly. There was only one thing in the universe she truly hated, and it was misery. But it wasn’t an angry hate, rather it was a depressed one.

“They raised him to be a killing machine. They physically augmented him and trained him for the sole purpose of war,” Twilight added. The others were shocked at these revelations, their mouths agape. “Mark told me the same story in Manehattan. He was in the first class of SPARTAN-IIIs. Most of them were eventually sent on suicide missions, and the ones that are still alive aren’t considered expendable”

“Are y’all serious!? They actually did that!?” Applejack burst out.
“Applejack, keep your voice down!” Twilight scolded her.
“What I’m sayin’ is, how could these fellas take innocent, vulnerable kids and turn them into unnatural monstrosities, then throw ‘em away?”

“Because they had to, AJ. Entire planets were being destroyed, and they were desperate…” Twilight spat, as though admitting such an atrocity was justified left a foul taste in her mouth.

“I admit, it’s hard to wrap one’s head around. To think that someone Sweetie Belle’s age could be turned into a killer…” Rarity shook her head in disbelief.

“Most humans don’t know that either, even though it isn't actually secret anymore, it's not common knowledge. They think it was a volunteer program, and they were treated like freaks for that. The only friends they have are each other, and they almost always work in small groups.”

“There’s something else Ethan and I talked about in that stable. I- I know it doesn’t make sense, but…” She sighed and drooped her head, her eyes closed. “I love him. And he said he loved me too. We kissed and held each other for a few minutes, and then he got AJ and I on the first flight out of Appleoosa. He said he’d be back soon.”

“Jason and I… It’s just that he’s really…” Fluttershy trailed off. Egged on by her friends’ stares, she continued, her cheeks red all the while. “He’s really sweet and gentle when you get to know him. He never swears, he’s smart a-and kind and helpful… And, I really miss him.”

“Mark doesn’t think he’s good enough for me. Princess Celestia doesn’t either. They both think he’s a monster, but I know he’s not, even if he’s done some...” She shuddered, and as she did she noticed that she was crying. “When I told him I loved him he broke down and hugged me. I think all he’s ever wanted was to be normal, but he couldn’t put his burdens on somepony else. I know that if Princess Celestia says it’s a doomed romance, then it is, but I still love him…”

***

“Hey flygirl!”

A distinctly human hand patted Rainbow Dash’s back, waking her from her dream. When she opened her eyes, she tackled Ethan in a bear hug before she even wondered how he got to her cloud-home. He wasn’t wearing his armor, and from his face he was clearly enjoying being on a cloud.

“Cloud-walking spell, extra-strength. I could be up here for weeks, and my stuff won’t fall down either.” He pointed to two crates and a duffel bag laying on her floor. “It’s rainy downstairs, so I hope you don’t mind if I crash here.”

“Sure. I really missed you Eeth.” Dash kept her forelegs wrapped around his neck, unwilling to let go.

“I missed you too, RB,” He murmured.

She got up and looked around. She must’ve fallen asleep on her couch, because she was in her living room. “So, how ‘bout I show you around? Me and the other weatherponies built a bunch of cloud bridges connecting most of the homes to Cloudsdale, so if somepony messes up their wing they’re not stuck at home.”

“Care to show me the sights?”

“Yeah! There’s a new Quentin Trotentino movie I’m dying to see.”

***

After seeing Ethan off, and Mark changing into fatigues, Twilight and Mark had a quiet breakfast together, leaving Spike asleep through the early hour. They sat next to each other at a counter, side-by-side.

“How’s Scootaloo doing?” Mark asked in between bites of pancakes. They were normal flapjacks edible by humans and ponies, rather than the hay variety.

“Better. Her foster parents are great ponies, and she’s pretty been happy with them, all things considered,” Twilight answered, some satisfaction in her voice.

“Good, I’m glad she’ll be okay. Twi…” Mark’s hand froze, and syrup dripped from the food he’d lanced as he agonized over something. “I just want to thank you for what you did back in Unikraine.”

“Mark, it’s fine, you don’t have to thank me.” She smiled gently at him, which only made him feel worse.

“Yeah, I do. I would’ve gone over to the Watchers’ Cabal if you hadn’t intervened… And I’m so sorry about what I put you through. For everything I’ve done since I met you.”

“It’s okay.” Twilight put a comforting hoof on his shoulder, which was protected only by a pale tan shirt.

Mark’s eyes began to water, but he held back tears and kept a mostly straight face. “I put you in danger, I killed a hundred fourteen ponies, I almost killed you on purpose. How is any of that okay?”

“Because I know what you did was hard for you, and that you regret it every day. As much as you want to believe you’re a monster, I know that in your heart you’re doing all this for the right reasons, or because you have so little self-esteem that you feel like you need to be punished more. But you don’t.”

She hugged him, and he held her close. It was extremely soothing to feel her mane against his cheek, especially with no beard to block it.

“You’ve had a horrible lot in life, but you kept going. Now I realize it wasn’t just your sense of duty; it’s because you had hope for your future. Maybe I’m that hope; maybe it wasn’t just chance that we met.”

Mark pulled back for a moment and looked at her.

“What do you mean?”

“Mark, neither one of us is normal. I’m an Element of Harmony, the Element of Magic, and the student of Princess Celestia, the most powerful pony on the planet. You’re one of only a few hundred humans who were strong enough to survive the most dangerous places in the galaxy, who could do repeatedly things few had the courage to consider doing once. Both of us have our burdens, our insecurities that we have locked away.”

He sat completely still, her point dawning on him.

“You’ve suffered for so long, but still been as noble as you possibly could in your situation. What if it was fate that we met? Fate that made us fall in love? What if the reason you haven’t died yet is because your story is meant to have a happy ending?”

Mark smiled as he felt his heart accelerate, and kissed Twilight’s lips gently, running his left hand across her cheek as she did so.

“Thank you.”

The rest of that day was spent peacefully, both of them happy to have this time together. A few ponies came in to the library that day, and they helped them with whatever they needed. After a cathartic conversation, it felt good to be generous. They just talked and read for hours, enjoying each other’s company. It was a very simple pleasure, but greatly satisfying.

Eventually, the two of them returned to the balcony to watch the sunset. The silhouette of the gold, orange and purple against the trees and mountains on the horizon had a divine beauty to it.

“Twi, I need you to do something for me,” Mark said as he gently ran his fingers through Twilight’s mane.

“Anything,” She answered. She smiled, and gave him a starry-eyed look.

“You know that no matter what, Equis or elsewhere, alive or lifeless, Heaven or Hell, I’ll always love you. But I need you to make me a promise.” His pained expression told her she wouldn’t like it.

“Okay?”

***

“Fluttershy, I need you to promise me that if I don’t come back-”

“Please don’t talk like that Jason,” The mare pleaded, wrapping her forelegs around his chest.

***

“I’m sorry Dash, but I’m still a soldier. If I have to give my own life-” Ethan tried to say.

“No!”

***

“Listen to me! I need you to promise you’ll move on,” Mark whispered, holding Twilight’s head in his hands.

“I- I can’t!”

“Yes you can! I’m not asking you to go on without grieving and to continue as if nothing happened. That would break my heart, wherever I end up going.”

***

“Then what are you asking?” Fluttershy whispered.

***

“I’m asking you to not grieve forever. I want you to be happy, Dash.”

***

“I just want you to be happy. Promise me that if I die you won’t spend the rest of your life grieving, that you won’t give up on life, or on love. Remember me, but don’t obsess over me.”

***

“I, Fluttershy-”

***

“I, Rainbow Dash-”

***

“I, Twilight Sparkle, promise that should you perish-”

***

“I will give up on neither life-”

***

“Nor love-”

***

“Nor the pursuit of happiness.”

Mark saw tears welling up in Twilight’s eyes, so he knelt down and kissed her cheek. “Have I ever told you how beautiful you look? You’re like an amethyst angel.”
She giggled, forgetting about the oath she’d just taken. “That sounds so corny.”

He grinned back at her and chuckled. “Yeah, I know… I wish we could have more time together. Because I’m in cryosleep so often I’m physically half my age. Now I’m beginning to worry I might outlive you.”

His worries were not lost on her, as she had some of her own. “My friends have been supportive of me, but… I don’t know if my parents or my brother would support what we have, let alone Princess Celestia.”

“Maybe we won’t get their support. Maybe we can’t prove to them that this is real.” He placed his hands on Twilight’s cheeks and brushed away her tears with his thumbs, gazing into her eyes with a gentle smile. “But it's real to us, that’s the important part.”

As the last rays of the sun died out, the stars appeared above them. They saw different things in the night sky. Mark saw the danger and horrors that lay among them, and Twilight saw the beauty of vast cosmic phenomena. Though they saw opposite things among the stars, in each other they saw the same thing.

“You’re right. Let’s make this our night. Let’s go back inside,” Twilight said. They entered her bedroom and shut the windowed door to the balcony, so that the only sources of light inside were a few candles and the moonlight. She lit the room with the glow of her horn. “I tried that humanization spell before, while you were gone. You remember the one I said I took from the Star-Swirl the Bearded wing because I thought it was dangerous to novices?”

Mark began to see what she was getting at, and he nodded. “Right?”

An intricate lavender rune appeared on the floor beneath her, glowing even as the candles were extinguished. It was mystical, the way the rune and the moonlight lit the room softly.

“I practiced it a few times, because I thought you’d like it, and-”

Before she could finish her sentence, Mark grabbed her, taking her to the floor with him, and began kissing her. He started at the bottom of her neck, working his way to her mouth with each subsequent peck.

By the time he reached her mouth, the two of them were levitating above the rune, spinning slowly in place.

“Maybe you could show me some other time,” Mark suggested, pulling his head away to look at her eyes as he gently ran his fingers through her mane.

***

The next morning, Mark awoke in Twilight’s bed, one arm draped over her slowly rising and falling chest, another under his own pillow. The room smelled of sweat and other scents, and he noticed the messy state of her mane. The soft smile on her muzzle told him she was happy, even in her apparent sleep. Her head lay atop his bare chest, rising and falling as he breathed. He closed his eyes again and kissed her nose.

Just before he drifted back to sleep, Mark thought about how happy he was. Although he still hadn’t forgiven himself for what he’d done, and he wasn’t sure what his ultimate fate was, as long as he had Twilight, he had a future.

“No one knows better than I that luck keeps passing me by ... that's fate,
But with you there at my side, I'll soon be turning the tide ... just wait,
As long as I've got arms that cling at all, it's you that I'll be clinging to.
And all the dreams I dream, beg, or borrow on some bright tomorrow they'll all come true.
And all my bright tomorrows belong to you,” He sang as quietly as he could.

Author's Note

Normally interspecies romances involving ponies that have lifespan-related concerns are when alicorns are involved. But since this is pre-alicorn Twilight (assuming she becomes one permanently), the pony is the one with the shorter lifespan. So I got to invert a FiMFiction trope.

Also, regarding the sex drive of SPARTANs...
From the Halopedia article on SPARTAN-II augmentations:

Catalytic Thyroid Implant

A platinum pellet is implanted in the left thyroid gland; this pellet contains a human growth hormone that is released into the body to boost growth of skeletal and muscle tissues. As the hormone is released into the body the pellet dissolves and is absorbed. The hormone targets and stimulates the growth of fast and slow twitch muscle fibers, effectively producing significant gains in muscle mass. The hormone also targets osteoblasts to help boost bone tissue formation and effectively strengthen the bone structure.[6]

2% of subjects acquire elephantiasis. Suppressed sexual drive.[6][5]

Keyword: "suppressed". We don't know if that carried over into the S-III Program and their seperate, safer augmentation procedures, Project CHRYSANTHEMUM. In fact, because the same procedures were used for S-IIIs and S-IVs, and DeMarco heavily implies sexual interest in Palmer (before finding out she's his CO) in the first cinematic for Spartan Ops. That means that the S-IIIs in all likelihood do not suffer from a reduced libido, or at least it's only moderately suppressed.