Notes: It's been a while, so I've written a catch-up below that will hopefully remind you of what's going on in this story!

Previously on 'Between My Captain & Commander': After six months of a casual threesome arrangement, Levi and Erwin acknowledge their feelings for Armin, and invite him into their relationship. This 'triad' situation is new to all of them, and they need to learn as they go along how to make it work.

In the previous chapter, Armin helps Mikasa with her plan to propose to Eren. On the same night, Levi and Erwin organise a late birthday surprise for Armin - with a romantic rooftop picnic and later a sexy role-play. Their encounter goes awry when Armin finishes with Erwin, instead of with Levi as planned. This creates tension, but ultimately Levi accepts the mistake and moves on.

Armin is keen to try out anal sex again, so they head into the bedroom to continue the night…

Chapter 25: Dreams and Reality

Erwin

After the three men moved into the bedroom, it became clear that Armin's show of confidence had been a skillful pretence.

The man lay out on the bed while Erwin massaged him. He was still wearing his trousers, but without his shirt and boots. His shoulders were stiff under Erwin's gentle hands.

Is he still worried over what happened earlier?

Little accidents like that would surely continue to occur in their relationship, no matter how much care and planning they put into their interactions. It was something they needed to accept and deal with. Still, that was easier said than done.

I'll take control of what I can for now — making sure Levi and Armin enjoy the rest of tonight.

For a start, he'd find out what was bothering Armin.

"Are you alright darling? You're very tense."

The librarian took a moment to respond. It always seemed to startle him whenever Erwin called him 'darling.' Probably because up to now, he only ever used the term for Levi.

"I guess I'm more nervous than I thought." Armin released a sigh, shifting away from Erwin and sitting up on the bed. "I've been looking forward to this all week. But now, I keep thinking of all the ways it could go wrong... just like the last time we tried."

His eyes tracked Levi, who was moving around the room lighting scented candles. The subtle fragrance of jasmine hovered in the air.

Erwin stroked Armin's arm. "Sex is never perfect. You're putting too much pressure on yourself."

"Will you be disappointed if we leave it for another time?" Armin asked.

"Yes. But we'll get over it." Levi dropped the matches into a drawer and climbed onto the bed beside his partners. "As much as we'd like to fuck you, we only want it if you do too."

Erwin smiled fondly at Levi's blunt honesty. "And remember anal intercourse isn't a requirement of this relationship. It's perfectly fine if you never feel comfortable doing it."

Armin's features softened. "Thanks. I'm still interested, but tonight doesn't feel right. Is there anything either of you would like to do instead?"

Erwin wracked his brain for possibilities. What could we do that both Levi and Armin would enjoy?

As abruptly as a lit candle, the perfect idea flamed to life in his mind.

He recalled a previous sexual request from Levi — one which he'd refused at the time. But after weeks of consideration, and given their new emotional intimacy with Armin, Erwin was far more open to the prospect now.

"Armin, are you against being involved in any type of anal intercourse tonight?"

The librarian tilted his head, brows knitted. "It depends what you mean."

"You've got that scheming look on your face, Erv. Where are you going with this?" Levi demanded.

"Do you remember that night about two months ago? When you asked for both me and Armin to fuck you?"

Erwin noted Armin's eyes lighting up with curiousity. Good, he's interested in the idea too.

At Levi's stunned silence, he continued, "Perhaps it's something we could try out now. What do you think?"

Levi rubbed his palms over the linen bed sheet, smoothing out a crease. He seemed to be struggling to maintain his composure.

"I mean, yeah, I'd be open to try it."

"So would I." Armin's gaze flicked to Erwin. "But are you really ok with it? You weren't comfortable with it last time."

Erwin took both men's hands. "Trust me, I'm happy to give it a go if it's something you both want too."

Armin's free hand traced circular patterns on the bed sheet. "Just remember, this is my first time topping someone. So don't get your hopes up or anything."

"Stop putting yourself down before you've even started," Levi said gruffly. "If you're nervous, we can try a position where I'm in control. Are you ok with that?"

Armin nodded, looking relieved at the suggestion.

Erwin's pulse thrummed with anticipation. "Why don't we start with a massage? Levi, can you take off your clothes?"

It was endearing to see his stoic partner getting flustered over being the centre of attention. Cheeks pink, Levi obliged by pulling off his clothes and lying face down on the bed.

Erwin and Armin took turns kneading his muscular back, digging progressively deeper into the flesh to work out any tension. Then they flipped him around and assaulted his body with kisses and bites, enjoying the embarrassed little huffs of pleasure he made.

Erwin took the lead when it came to preparing Levi for anal play. His slicked finger teased at the man's entrance, before sliding inside and expertly locating his sensitive spot. Levi bucked his hips, whimpering at the sensation. Armin whispered encouraging praise and stroked his dark hair. Levi's eyes fluttered closed as he lost himself between the two men.

Erwin gestured for Armin to swap places with him. When Armin moved down the bed, he muttered, "Just take it slow, ok?"

Armin jerked his chin in a determined nod before moving between Levi's legs. He'd helped prepare the man like this once before, so it wasn't brand new territory for him.

Levi tensed at this less familiar intrusion. Erwin dipped down to take his cock in his mouth as a distraction. The man's strong, lithe body rose and fell in time to his movements. From what he could see at the corner of his eye, Armin's fingers were copying the same careful rhythm.

"Fuck!" Levi gasped after a few minutes. "That's enough, let's get on with things."

Under Levi's instruction, Armin tugged off his remaining clothes and sat at the edge of the bed. He accepted the bottle of oil from Erwin and slathered a generous amount over his erection. Then the Captain swung a leg over him to straddle his lap.

Erwin ran his hands encouragingly over Levi's back and buttocks, conveying his approval for what was happening. The man trembled under his hands.

"Walls… you have no idea how good you two look right now," Erwin sighed.

Levi's muscles relaxed at the words. He wrapped his arms around Armin's neck and allowed Erwin to guide his hips over Armin's cock.

"You're so tight," Armin gasped when Levi sank down a little on him. Levi manoeuvred himself all the way down, eliciting more gratified noises from the man under him.

Eager to stay involved, Erwin grasped Levi's midriff. With carefully movements he directed him up and down on Armin. The librarian broke into ragged panting. His gaze flicked between the man on his lap and Erwin standing behind him, as if unsure who to focus on.

Maybe I should give him some attention too…

Releasing Levi, Erwin clambered up onto the bed behind Armin, sliding his arms around his lean waist in a tight grip. He lay a trail of kisses over the sensitive skin at the back of his neck. Armin's shoulders hunched, breath coming in frantic huffs.

Sensing something was wrong, Erwin asked, "Are you ok?"

Armin's silence was confirmation enough. He stared fixedly at a spot on the wall, just past Levi.

Levi stopped his movements, settling back awkwardly on Armin's thighs. "What is it?"

"It's just... this is…" The sentence trailed off and he shook his head.

"Just say it, you can tell us anything." Erwin pulled back, giving the man space. Levi clambered off him to sit on the bed.

Armin exhaled a shaky breath. "Having both of you involved for this feels a bit… overwhelming. Would you mind if I spent some time alone with Levi first?"

Icy tendrils snaked around Erwin's heart, cooling the flames of his passion.

He's never shown any issue with both of us being involved before! Why the sudden change?

"I'm not comfortable with Erwin leaving the room," Levi said firmly, crossing his arms over his bare chest.

"I wasn't necessarily asking for that." Armin's mouth twisted, eyes downcast. "Sorry. I shouldn't have said anything."

"No, it's good you spoke up." Erwin's hand settled reflexively on the man's shoulder.

Reigning in his turbulent thoughts, he considered things from a different perspective. In his effort to be supportive, had he been crowding his partners? Unintentionally asserting dominance over the situation?

This was Armin's first time topping someone, and he obviously wanted it to be a meaningful experience. Perhaps having a third man involved in the act was too much for him to handle right now.

It's not like he's demanding anything — he's just being honest about how he feels. It's what we all need to do to make this relationship work.

Erwin searched for a compromise. Forcing aside the shards of his pride, he said, "What about if I just watched for now? Would that give you enough space Armin?"

"Yes, I think so."

"You sure you're ok with this Erv?" Levi's dark eyes betrayed his uncertainty. "We can always do something else."

Erwin covered both their hands. "I'm sure. And if you still feel up for it Levi, I'll take over after Armin finishes."

Not wanting to drag this disruption out any longer, Erwin moved to the chair in the corner of the room. The same one Armin sat in on their first night with him, when he'd watched Levi and Erwin have sex together.

The other two men hesitantly resumed their activities. This time, Armin pulled Levi tight to his chest, creating a cosy intimacy between them. Levi's head fell forward over Armin's shoulder, as he gripped the man's upper arms and slowly rose up and down on his lap.

Their mingled pants and sighs of pleasure made Erwin's stomach flip. The ice in his veins rapidly melted, to be replaced with a blaze of affection.

I can't blame Armin for wanting time alone with Levi — he's able to connect more deeply with him now, without any distractions.

Levi halted his motions, pulling back to survey Armin.

"You want to do something different? How about bending me over?"

Armin threw his gaze at their partner watching them. "Are you ok with that, Erwin?"

"Definitely." Erwin shot them a smirk, appreciating that they'd checked in with him.

It was killing him to just sit there and watch. But Armin had been relegated to the very same role many times during their threesome arrangement. With the shift from a casual to committed relationship, it was time to offer the man more freedom and control.

If that means I have to take a backseat from time to time, then so be it.

Levi clambered off Armin's lap and bent over the bed. The librarian's confidence had clearly grown, because he didn't hesitate before standing behind him, running his hands over his hips and ass. After whispering a question to Levi, and getting an affirmative grunt in response, he carefully began entering him.

Erwin immersed himself in the voyeuristic thrill of the experience. With each moan of pleasure and every thrust, his cock twitched as if he were involved in the action. One hand gripped the armrest while the other flexed on his thigh. He longed to touch himself. But waiting would make his eventual release all the sweeter.

Perhaps I should suggest that they finish things off without me? They're really getting into this…

Armin's full attention was fixed on the man before him, brows furrowed in concentration. Erwin knew Levi could take much heavier thrusts than what the librarian was giving him. But he bit back voicing this suggestion, not wanting to throw him off.

In any case, Levi was clearly enjoying Armin's efforts. Erwin had a perfect view of his scrunched up face in the flickering candlelight. The Captain's hands fisted the bed sheets, heedless of making a mess of them.

"Fuck, Erwin!" he moaned.

Armin's movements stalled. He locked eyes with Erwin, an unreadable expression etched across his features.

Levi was staring at Erwin now too, brows pinched and mouth set in a grimace; evidently realising he'd called out the wrong name.

The perfect words to resolve the situation eluded Erwin. So he watched on in silent dread, praying his partners could figure this out by themselves...

Levi

"Do you want Erwin to take over?" Armin's words stung with resignation.

"No. Fuck, I didn't mean to say that." Levi squeezed his eyes shut. He couldn't bear to look at Erwin anymore, who was still seated silently in the corner of the room. Even the calm Commander couldn't think of anything to salvage this.

Armin's fingers brushed over his back in a gentle caress. "It's fine, don't worry."

Levi tried to speak, but only a strangled noise came out. He'd just dealt a solid blow to Armin's self-esteem. He didn't deserve this sympathetic understanding from him.

How did I manage to ruin everything with a single careless word?

Levi glanced back up at Erwin. Had his guilty conscious been the reason for his verbal slip? It felt so good getting fucked by Armin… too good… It was confusing to be doing this with another man while Erwin sat back and watched.

"I don't mind swapping places with Erwin. Just tell me what you want," Armin urged.

Just be honest with him. I'm sure we'll figure something out…

"No, I want you to continue. But do you mind if Erwin comes back over? It feels weird not having him here."

To his relief Armin agreed, and Erwin returned back to them. Together the trio discussed a way to continue that they were all comfortable with.

Levi lay down on the bed, placing a towel under his hips so they wouldn't make a mess of the bed sheets. Armin crawled on top of him. Erwin lay sideways beside them, focussing his attention on Levi as Armin slowly entered him again.

Both men's hands travelled over Levi - Erwin charting the planes of his chest and stomach, while Armin gripped his thighs for leverage as he slid in and out of him.

"You can go harder if you want," Levi panted.

Armin obliged, his thrusts growing deeper. He maintained the same steady rhythm as before. Levi couldn't help but think that if it were Erwin fucking him, he'd have picked up the pace by now.

But he's not Erwin. And I don't want him to be.

"Do you want me to pull out before I finish?" Armin asked breathlessly.

Levi grit his teeth to stop the word 'no' from escaping his mouth. How did his other partner feel about this?

"I'm fine with him finishing inside you." Erwin's hot breath tickled Levi's ear. "It's up to you darling."

The man's enthusiasm burned away his lingering guilt. I've fantasised about the two of them coming inside me for so long… now here's my chance.

"I want both of you to come inside me. One after the other," Levi demanded.

For the first time since switching to this position, Erwin's gaze focussed on Armin. His mouth curved into a satisfied smile, and the librarian returned the conspiratorial look as if sharing a joke.

"Stop smirking at each other, and hurry up and fuck me already!"

Armin obeyed the order. He plunged back into Levi, angling his hips higher to allow for deeper penetration. Despite the measured pace, pressure mounted in Levi's every nerve and muscle. Each thrust edged him closer and closer to his own release.

Should I hold back? Maybe Erwin would prefer for me to finish later when he's topping me-

The concern disintegrated as Erwin's hand wrapped around his cock. After a few teasing strokes, he circled his thumb over the leaking tip.

"Are you going to come for Armin?" he asked.

Soon Levi was reduced to a moaning, squirming mess as one lover pounded into him, while the other pumped his cock in languid strokes.

"Armin!" he moaned. "Fuck, right there."

Erwin brushed Levi's dark hair back from his forehead. "You're such a good boy, taking his cock so well."

Overcome between both men, the Captain's eyes drifted closed. Erwin's free hand roamed possessively over him, mapping out a trail from his throat down to squeeze his upper thigh. On the same leg, Levi felt Armin's grip slacken. Through slitted eyelids he saw the man readjust his hand to cover Erwin's.

Armin finished with a long moan, buried deep inside his partner. In response, Erwin's motions on Levi's cock turned merciless. It was enough to push him over the edge. With a final broken whine he finished too, riding out his orgasm right after Armin's.

The librarian leaned forward to brush lips with him, before carefully pulling out.

"Are you ok? Are you sore?"

"Please, I'm Humanity's Strongest Solider." Levi's reply was a weak growl.

Erwin rubbed his shoulder. "Are you sure you haven't had enough? We can leave it there for tonight."

"Just fuck me, Erwin."

"Well, since you asked so nicely…"

The man didn't drag things out. After pulling off his shirt and trousers, he crawled on top of his partner, just as Armin had done earlier. But Erwin changed things up this time. He lifted Levi's legs, leaving his ankles resting against his broad shoulders. Without preamble he slid inside him, and soon set a swift pace.

Trapped under this relentless assault, Levi stammered incoherent pleas, face scrunched up and lips quivering, head thrown back against the pillow.

"You love having two men looking after you, don't you Captain?"

Levi's body protested at this second intrusion, his overly sensitised prostate shuddering with every thrust. Part of him registered revulsion at the mess trickling onto the towel under his hips.

But Erwin was right. He fucking loved it.

Just as Erwin's movements grew erratic, Armin returned to the bed.

"You're such a good boy for us," he whispered, brushing hair off Levi's sweaty face before squeezing his hand.

With a guttural groan Erwin finished, slamming into his partner one last time.

Afterwards, Levi lay sprawled on the bed as his two partners embraced him. His body ached, involuntary tears stained his cheeks, and things down there were an unpleasant sticky mess. But all he felt was a blissful daze of satisfaction.

I can't fucking wait to do this again…

Armin

Armin stood under the shower, hot water cascading down his body and easing his tired muscles.

The night's activities swirled around his head like a spoonful of honey stirred into tea. He weighed the sweetness against the bitter — unable to decide whether their first encounter as a committed triad was a success or not.

Was Levi still annoyed over his and Erwin's mishap during the role-play earlier? Had Erwin, in his typical polite way, covered up his hurt when Armin requested some space? And had Levi actually enjoyed having Armin top him, or was he just thinking about Erwin the whole time?

The last thing I want to do is discuss any of this with them tonight...

But that's exactly what I need to do.

Armin turned off the water and dried himself. Wrapping a towel around his waist, he opened the bathroom door, walked down the hall and returned to the bedroom.

Levi was already finished his shower and dressed in pyjamas. The splash of water from the en-suite told Armin that Erwin was showering in there.

"You should start leaving your own stuff here. Not that I mind you borrowing my things." Levi rooted around in a drawer, pulling out a pair of pyjama bottoms and one of his own t-shirts.

Armin accepted the clothes. "Thanks. So… you're still ok with me staying the night?"

"Of course." Suddenly Levi's eyes narrowed, and he leaned in to appraise Armin's neck. "Shit! I must have bit you too hard earlier. You should wear something with a high collar tomorrow."

"Is it that bad?" Armin groaned, rubbing at the itchy part of his neck.

"Sorry. I guess I got carried away."

Armin's face flushed at the memory of being pressed between both men during the role-play. "Don't worry. It was worth it."

He pulled on the pyjamas and they both climbed into bed. He would miss having the excuse to wear Levi's clothes when he came over.

But keeping some of my stuff here makes the relationship feel more official. Just like how they gave me that key earlier.

Levi wrapped his arms around Armin from behind. The hard muscles against his back were oddly comforting.

"That was amazing earlier. I hope you're not sore?"

"A little bit." Levi squeezed him tight to his chest. "But it was worth it."

Armin's stomach fluttered, uneasy relief spreading through him. So he enjoyed it too?

Erwin returned to the bedroom. His face lit up at the sight of his two partners already cuddling in bed.

"I see you didn't bother waiting for me?"

"Get in here and help me warm up this cinnamon roll," Levi ordered.

Armin wriggled in Levi's grip. "Why are you still calling me that?!"

"Because you hate it so much."

"I can't believe you two are bickering again." Erwin slid under the covers, wrapping an arm across both men. "I'll throw you out if you can't be civil."

"Levi started it," Armin muttered.

In response, the Captain dug his surprisingly sharp elbow into Armin's side.

An exasperated Erwin decided their 'play' was getting too serious. "I'm not letting you two murder each other tonight. Armin, you move over to my other side."

Armin dutifully moved, so he was on the edge of the bed and Erwin was now in the middle. It was probably for the best. His banter with Levi might be part of their usual dynamic, but it clearly wore on Erwin's nerves at times.

Armin sank into the larger man's arms, trying to convince himself that it was far too late to start up a serious discussion. Maybe he should wait until their next meeting.

But there's no way I'll be able to sleep tonight if I don't get answers.

He cleared his throat. "Do you mind if we talk about how things went tonight?"

"Sure, go ahead." Erwin paused before adding, "How are you feeling?"

"Pretty good overall. But I feel bad for asking you to give me and Levi some space. Was it too early for us to try something like that?"

"Well, I admit I was a bit hurt at first. But then I realised you wanted to connect one-on-one with Levi, and I was happy to give you that." A smirk spread over Erwin's features. "Besides, I love watching the two of you together."

Some of the knots in Armin's stomach unravelled. Maybe he'd been blowing everything out of proportion… but what about Levi? The man was currently twisting the bed sheet cover in his hands, a sure sign of a troubled mind.

"Are you ok, Levi?"

"I – I was uncomfortable when Erwin wasn't participating tonight." He ground the heel of his palm into his face. "I'm still open to us having separate relationships with you. I just think it'll take some time — maybe a lot of time — before I'm ready to do anything sexual with you without Erwin there too."

"That's ok. And there's no obligation for me to top you again, if you don't want that."

Levi shifted to face him. "Wait, did I forget to say how fucking good you were? I definitely want to do it again."

Armin grinned. "So do I."

"Next time we can discuss the details beforehand, and figure out something that suits everyone." Erwin yawned and snuggled in closer to Armin. "But perhaps our next meeting should be sex-free. Armin, are you free on Wednesday evening?"

Armin confirmed this suited him. They all said goodnight, and settled down to get some much-needed sleep.

Armin was about to knock on the door of Erwin's quarters, before recalling that he now had a key. Smiling, he pulled it out, unlocked the door and entered. Levi and Erwin were already having tea in the sitting room.

"There you are. We need to talk." Levi poured out a teacup and handed it to him. Then the Captain sprawled sideways on the couch, stretching his arm lazily over Erwin's shoulders. Between the two of them, there was no room left for Armin. So he sat opposite them on the armchair.

"So we've been talking… and I'm sorry to say this isn't working out." Erwin's tone was kind but business-like, as if they were at a meeting. He placed his hand over his partner's. "We've really enjoyed our time with you Armin. But we think it's best to stop now before we invest too deeply in something that — quite frankly — probably won't work out. Have you any questions?"

The teacup scalded Armin's hands. But he didn't put it down. The pain was a welcome distraction from the numbness spreading through him.

"We can still be friends." Levi spoke like he was offering a scrap of food to a pathetic, starving animal.

"But I'll need that key back," Erwin said, politely apologetic.

The key was still in Armin's hand. He placed it on the table, next to the teapot the men had served him tea from countless times.

"Well, I'm glad that's over with." Levi leaned closer into his partner. "Do you want more tea, Erwin?"

The two men began discussing their plans for the weekend. Armin sat in silence, his trembling hands sending tea sloshing over the side of the cup. A sob broke out of him. He covered his mouth, afraid the men would be angry at him for making a scene.

But they didn't even notice.

"Armin?"

He woke with his pulse racing, sweat beading under his pyjamas. Erwin touched his arm in the darkness.

"Are you ok? You were moving around a lot in your sleep."

"Yeah, it was just a bad dream."

Armin rubbed his eyes, heart still hammering. He frantically tried to ground himself in the present. Erwin was massaging his shoulders in soothing circles, and he could hear the steady rhythm of Levi's breath on the far side of the bed.

But shaking off the remnants of the dream was easier said than done. The claws of panic scratched at his senses, refusing to listen to reason.

What he craved more than anything was the solace of his own bed. At least there he wouldn't have to worry about keeping the other men awake.

"I might go back to my own room if that's ok?"

There was a pause. Armin knew it shouldn't be a big deal. After all, even Levi didn't stay with Erwin every night — he slept in his own quarters most of the time. There was no expectation that they all share a bed just because they were in a committed relationship.

Erwin brushed his lips over the top of his head. "Alright darling. Don't forget your presents in the sitting room."

Darling. The word always gave him a jolt. It was usually Erwin's endearment for Levi, after all.

Armin slid out of bed. Groping around in the dark, he found the chair where he'd left his clothes. But wait… where was his shirt?

Not wanting to wake Levi with his searching, he decided to stick with the t-shirt he was already wearing. Levi wouldn't mind him borrowing it. After swapping his pyjama bottoms for his trousers and pulling on his shoes, he crept out of the bedroom and down the hall.

He paused to collect the paper bag containing his birthday presents — the delicious little mochi cakes, the beautifully illustrated astrological book…

And a spare key to Erwin's quarters.

His feet carried him on the familiar path out the front door and down to the ground floor. But he hesitated at the door of his own quarter's.

There's no way I can sleep right now. Maybe a stroll in the night air will help me relax?

He entered his room and dropped the bag on the bed. On impulse, he dug around in it to find the little box containing the key. After slipping it into his pocket, he grabbed his cloak and ventured outside the building.

Only a few hours earlier, he'd viewed the Survey Corps grounds from the rooftop with Levi and Erwin. Everything looked so idyllic from that lofty perspective. But now the cool night air burrowed under his clothes to prickle his skin, and the buildings cast long crooked shadows in the moonlight. He wrapped his cloak tighter around himself and strode on.

Fragments of the night swirled around his head. Not just the sex, but also the effort Levi and Erwin put into making him feel a part of their relationship. A flush spread across his body, creating a temporary barrier of warmth against the cold. He felt like he was soaring through the clear moonlit sky.

Then the memory of his dream sent him plummeting back to the ground. He struggled to breath, choked by the terror that their relationship was doomed to end in heartbreak. His doubts stacked up higher and higher in his mind, like a house of cards. How long before everything came tumbling down?

He reached the cover of the trees, their leaves rustling in the breeze. He walked on, not ready to turn back yet. Nestled under his barbed worries was a single fear that refused to go away, no matter what kind gestures or reassurances Levi and Erwin offered him.

What if by pursuing this triad with me, they'll end up sabotaging their own relationship?

Armin's fingers traced the box in his pocket. He pulled it out and snapped open the lid, lifting out the plain brass key. He squeezed it in his palm, the ice cold material burning into his hand.

All he wanted was their love.

But at what cost?

"Armin?"

He shoved the key back in his pocket. Eren and Mikasa were strolling through the trees towards him, their arms linked, both wrapped up in heavy coats.

Damn it, I forgot about their picnic tonight!

A huge grin stretched over Eren's face. He unhooked his arm from Mikasa and launched himself at his best friend, engulfing him in a bone-crushing hug.

"Armin you won't believe it — Mikasa insisted that we have a midnight picnic tonight, and then out of nowhere, she proposed to me!"

Eren proudly displayed the steel ring hanging from a chain around his neck. The one Armin had helped Mikasa pick out in the jeweller's shop a few weeks ago.

Mikasa's lips twitched at her fiancé's exuberance. Her cheeks were pink, probably more from embarrassment than the cold.

"But wait… what are you doing out here Armin? Did you know about this?" Eren swivelled his gaze between them. "Is that why the two of you have been sneaking around together lately?"

A strange concoction of emotions was bubbling inside Armin — his eyes stung and he couldn't quite catch his breath. Eren and Mikasa's joy was almost too much to bear.

Get a hold of yourself! Pretend you came out here to meet them on purpose.

"I'm so happy for you both." He pulled Mikasa into an embrace and whispered, "See, I told you he'd say yes."

Her face shone, eyes sparkling. "Thank you. I wouldn't have been brave enough to do this without your help."

With all the hugging, Armin's cloak hung loose on his shoulders. Mikasa's gaze settled on his neck. A crease wrinkled her brow. She glanced at him up and down, before focussing on his torso.

Armin shivered under the scrutiny. Why the hell is she staring at me like that?

Then it hit him.

She must have spotted the mark Levi left on his neck. But that didn't explain why she was now staring at his chest.

Mikasa finally lifted her gaze. She asked in an undertone, "Were you with someone tonight?"

Armin released an awkward laugh, unsure how to answer. He glanced down as he tugged the fabric of his cloak tighter around himself. And his heart froze mid-beat.

He was wearing Levi's t-shirt.

FUCK. Does Mikasa recognise it?

It was black and long sleeved, nothing like anything Armin owned. In fact, he couldn't think of anyone else except Levi who wore t-shirts like that…

But that doesn't mean anything! Mikasa can't know anything for certain just by a damn t-shirt!

Eren seemed utterly oblivious to the tension between his best friend and his new fiancé. Hooking his arms in both of theirs, he steered them through the forested section of the grounds, babbling happily about this being the best day of his life.

When Eren's boisterous excitement finally simmered down, Mikasa said in a querying tone, "Armin-"

Stomach clenching, he interrupted her. "When are you guys going to tell everyone the good news?"

"As soon as possible!" Eren turned to his fiancé. "So long as you're ok with that, Mika?"

She grimaced. "Yes. Let's get it over with."

"Oh come on, it won't be that bad."

"Easy for you to say. You love attention."

"We should have a really big wedding too, we're only going to get married once after all!"

Mikasa squeezed her eyes shut. "You know, I'm starting to regret proposing to you. I can't believe you talked me into this, Armin."

"Wait, you're blaming me?"

"Fine! We don't need a huge wedding. Let's just elope without telling anyone."

"Sounds good to me." Mikasa turned towards Armin, her smile fading. "It's pretty late. I think it's time we all headed to bed."

He watched the couple go, the sound of their laughter echoing back to him.

What would it be like to experience that sort of easy relationship? Not having to keep it a secret, or fear judgment from others?

Armin trudged back to his quarters. He concealed the key in his nightstand before collapsing into bed.

It had been nice to meet Eren and Mikasa earlier, and share in their happiness. But his carelessness weighed like an anchor in the pit of his stomach. Had Mikasa realised he'd been wearing Levi's t-shirt? Or was he just being paranoid?

Whatever the case, he needed to warn Levi and Erwin of Mikasa's possible suspicions.

A warning that would involve confessing to his own stupid mistake.

I hope I haven't messed everything up…

Notes: So this chapter was… challenging to say the least. There's lots of things I want to explore in regards to the triad relationship, but unfortunately there's not enough space. Picking and choosing what to focus on isn't easy, but I hope I'm managing to keep this story interesting.

I'd love to hear what you think of this chapter – the smut, the triad conflict, Mikasa's suspicions, and the future of Armin/Levi/Erwin's relationship?