Previously: Levi invited Armin to join a threesome with him and Erwin. Armin is interested, but needs to think it over. Levi still needs to discuss the matter with Erwin too.

Finally some smut in this chapter, I hope you enjoy!

Chapter 5: Forbidden Fantasies

Armin

Armin went straight back to his dormitory after dinner. Eren and the other boys would be hanging out in the recreation building for at least another hour or two. So he had some time alone to process what had happened earlier.

Levi's sudden proposal made no sense. At first he thought the whole thing was a sick joke. But he couldn't imagine Levi doing something like that. Despite the Captain's teasing, he seemed quite serious about the matter. And he sounded genuinely apologetic when he thought he'd upset Armin with the proposition.

When in reality, Armin had just been struggling to wrap his mind around the unbelievable offer.

A threesome. With the handsome, charming, intelligent Commander Erwin who he'd been having illicit fantasies about for months now.

While on the other hand, there was Captain Levi – who was undeniably attractive, but his very presence still put Armin on edge.

Weighing it all up, the entire thing could turn out to be a complete disaster. He should find Levi, right now, and tell him he wasn't interested.

But something deep inside him protested. I'm always cautious and sensible about everything. What would happen if I give into my impulses for once?

With a shiver, Armin recalled Levi's actions earlier. The Captain's small but strong body had backed him against the wall, as he'd first given him a warning, and then that surprising proposition.

Armin's skin tingled as details came flooding back - how Levi had gently brushed a strand of hair off his face, squeezed his shoulder reassuringly, and that elusive, half-smile on his lips.

Had Levi intended the encounter to be so blatantly sexual? Or was it simply Armin's overactive imagination? Then again, the man had invited him to join a threesome. His actions were likely somewhat intentional.

Am I seriously imagining sleeping with my Captain? He acts so aloof and emotionless, nothing at all like Erwin…

But Levi seemed like a decent man. While he mostly only instructed the elite soldiers, Armin had participated in several of his specialised training sessions for all soldiers. He never criticised him when he fell behind his team mates like other instructors did, but simply offered practical advice to encourage him to keep trying. He was blunt-spoken, but never cruel or insulting.

And then there was that mortifying incident last year. Armin's heart clenched just remembering it…

He and Jean had snuck into a secluded supply closet for a few minutes alone. Things had gotten a bit more heated than they'd intended. Jean had Armin pressed to the wall, pinning his hands against it, and kissing him furiously.

Of course, that was when Captain Levi walked in. They'd both stammered apologises to him, and fled the room as fast as possible.

When Levi approached Armin on his own later that day, he'd expected a stern lecture about the inappropriateness of his actions. And perhaps some sort of cleaning related punishment.

To his utter shock, Levi asked him if everything between him and Jean was consensual. He'd assured Levi that Jean wasn't pressuring him into anything. He'd felt a twinge of shame at being singled out – why did Levi feel the need to check up on Armin, and not Jean? But he supposed when Levi had walked in on them, things might have looked a bit forceful. He had no way of knowing that Armin was enjoying it.

Despite his embarrassment, Armin had been oddly touched. Experiencing the Captain's kindness first hand was like getting a glimpse under his harsh mantle as Humanity's Strongest.

Earlier today, it had happened again. Armin completely understood the man's initial intimidating manner; he didn't want his and Erwin's secret to get out. Despite this, Levi's rough teasing had been like an exhilarating game. He clearly approved when Armin broke through his fear and spoke his mind. Those tantalising words kept echoing in his mind: "I'll play nicely, if that's what you want."

The prospect of the stern, strong Captain being considerate to his needs sent heat rushing through his body.

Armin had been touched by how both men were more concerned about the other's reputation than their own. There seemed to be a deep bond between them, which Armin was curious to discover more about. He couldn't deny he was envious of that sort of love, any more than he could pretend he wasn't jealous of Eren and Mikasa's relationship.

If I go ahead with this, it'll only be about sex. I can't go getting any dangerous feelings about either Levi or Erwin. Obviously this whole thing is just some sort of fantasy they want to experience…

Armin could cope with a purely physical arrangement. After all, he and Jean had hooked up based on the fact they both liked men. They'd called it dating, but really the whole thing had been a casual exploration of their mutual desires.

But his awkward experience with Jean paled in comparison to the passion he'd witnessed between Levi and Erwin last night. He couldn't believe he'd been invited to share in that with them.

That's if Erwin was interested too, of course. A thrill raced through him as he recalled Levi's conviction that he would be. Still, Armin had his doubts. How could Erwin be in love with a man like Levi, and have feelings for someone like Armin, who was probably the complete opposite of his lover?

Or perhaps that's where the appeal lay, the fact he was so different.

He forcefully pushed aside some of Floch's old scathing remarks about his soft, 'feminine' appearance and manners. While they might have hurt a few years ago, Armin was more confident these days. Floch had just been trying to hurt him in any petty ay he could.

Besides, Mikasa was quite masculine looking, but was considered one of the most attractive women in the Survey Corps. So there was nothing inherently wrong with not matching outdated gender ideals. And while Armin was still a bit insecure about his small stature, he knew he was at least somewhat attractive, based on Jean's interest in him and comments his friends had made.

Armin lay down on his bunk, feeling hopelessly out of his depth.

How does a threesome even work… Do we all take turns with each other, while the third person watches? Or will all three of us participate together? Will it be awkward, joining their relationship like that? Should I have explained to Levi about my limited sexual experience, in case that puts them off? What if they have unrealistic expectations of me?!

Armin had no way of finding out more information, without asking. It wasn't exactly a topic he'd read about in books. Not the books he had access to, anyway.

He tried imagining it, to figure out logically how it could work. Despite his doubts and inexperience, he couldn't contain a surge of excitement as possibilities flashed through his mind.

Armin didn't expect Eren back to their shared dorm anytime soon, which granted him some precious privacy. He settled back against his pillow and closed his eyes.

His thoughts sprang back to the scene he'd inadvertently witnessed in Erwin's office. Only this time instead of Levi, it was Armin bent over the table. His Captain and Commander stood behind him, out of his sight. Even though he was fully dressed, he felt vulnerable to have these two powerful men standing over him.

A hand trailed gently down his back; starting at the sensitive nape of his neck, and all the way down to caress his ass.

"You look so good, Armin," murmured the deep voice of his Commander. His approving tone sent a spike of arousal through him.

His hand moved away to be replaced by another. This hand gave his backside a sharp slap, making Armin jump. The sensation was confusing, but not unpleasant.

"You don't know how often I've thought about doing that, watching you train in that tight uniform," Levi growled.

Hot breath tickled his ear. "You're such a good boy, Armin," Erwin murmured. "I never thanked you for helping me with my files a few months ago. I think you deserve a reward. What do you say, Captain?"

"Hmm… I might just help you with that reward." Levi's words dripped with enthusiasm.

And just like he had done with Levi that night, Erwin gripped Armin by the hips, and easily flipped him around. Armin faced his Commander; who was dignified as usual, but with a small, possessive smirk on his face. Levi stood beside him, equally poised, but with a hungry gleam in his grey eyes.

Erwin positioned Armin so he was perched on the edge of the table, his legs barely touching the floor. "Do you want the honour, or should I?" Erwin asked Levi politely, as if they were at a formal gathering.

"You go first, and I'll watch. Maybe I'll have a turn after."

"Very well." With his big hands, Erwin lifted Armin slightly off the table and tugged down his trousers and underwear. Even in the daydream, Armin felt his face burn with self-consciousness at his body's evident enjoyment of the situation.

"Good, you're already ready for me," Erwin said in a pleased tone. He knelt down between Armin's legs. He gripped the younger man's thighs in his hands, his thumbs circling a gentle pattern on his sensitive skin.

Erwin's hot breath teased his aching erection, before he dipped his head and captured it in his mouth.

In reality, Armin had only experienced this sensation with Jean. It had felt good, sure; but also messy, rushed, and slightly uncomfortable.

But his stimulated imagination blocked out any awkwardness. All he could think of was the Commander's hot, wet mouth around his cock. He moaned involuntarily, both in the dream and real life. This seemed to encourage Erwin, who took him fully in his mouth, and began a rhythm of sliding up and down his length.

Armin had almost forgotten about the Captain, until he perched on the table beside him.

"You're not going to ignore me while my boyfriend sucks you off, are you?" he demanded. Leaning in, he gripped Armin's shoulders and swooped in for a hard kiss.

In real life, Armin stroked himself, while imagining the overwhelming sensation of Levi's tongue in his mouth, and Erwin's tongue twisting around his sensitive cock.

He came into his hand with a loud moan. Still panting, he grabbed a towel and quickly cleaned himself up before Eren returned to the dormitory.

And he'd finally made a decision.

He knew the safest and wisest thing to do was refuse Levi's offer, and keep his illicit desires locked away at the back of his mind forever.

But every fibre of his being was burning with curiosity. Would the reality of sleeping with these two men be just as mind-blowing as his fantasy? Would he ever be offered an opportunity like this again?

Maybe for once in my life it's time to take a risk - and follow my heart instead of my head.

Erwin

After the stress of their little 'interruption' the previous night, Erwin and Levi indulged in a bottle of wine that evening in Erwin's quarters.

"We don't need to worry about Armin. He promised not to talk about it," Erwin assured his partner. He frowned, staring into his glass. "I wanted to ensure he understood the gravity of the situation, but I think I scared the poor man."

He recalled the way Armin had frozen up, his breath ragged like he was having a panic attack. He couldn't blame him for not wanting to discuss it. The whole situation was mortifying. But still, he'd needed to get the truth out of him. And the young man had been in better spirits by the end of the conversation. So there didn't seem to be any harm done.

Levi took a sip of his wine and remained silent. It wasn't uncommon for him to take his time replying. He sometimes struggled to find the right words to express his thoughts. It was a reason he often ended up sounding unintentionally abrupt or harsh.

Right now, the man was wearing loose comfortable clothes instead of his pristine uniform. He'd taken his boots off, and his legs were drawn up underneath him.

Humanity's Strongest Soldier - curled up like a lazy, contented housecat.

I'm so lucky I get to see this side of him, Erwin thought fondly.

Finally, Levi replied. "Poor boy indeed… He was interrogated by both his Commander and Captain today."

Erwin's fondness melted into apprehension. He put his glass down on the table.

"Wait, you talked to him too? I told you I'd handle it."

He loved Levi more than anything, even if he wasn't always the most tactful or sensitive with others. Erwin was used to his abrasive ways, but Armin on the other hand…

"He's still in one piece, don't worry," Levi waved a hand dismissively.

"What did you say to him?" Erwin tried to keep his voice calm. Surely Levi wouldn't act so frustratingly composed If there was any need for concern.

"I just reiterated that he shouldn't spread gossip with his bratty friends. Oh, and I also found out he's single. He's not involved with Jean Kirstein anymore." Levi's lips quirked mischievously.

Erwin's heart raced. "Levi! Why would you ask-"

"Don't tell me you're not curious about him?" Levi raised an eyebrow.

Erwin's head was spinning. He was used to being in charge and in control of things. But Levi had a knack of knocking his organised life into chaos. It was something he both loved and hated, depending on the situation. He wasn't sure yet which one this would turn out to be.

"Please just tell me what you're getting at." Erwin had a suspicion, but he wanted it confirmed.

"You remember that talk we had a few months ago?" The smugness dropped from Levi's voice, and his expression turned serious. "Where we discussed my interest in more varied bedroom activities?"

Erwin remembered it well.

They'd encountered issues over sex early in their relationship. Levi had been cautious, almost ashamed of sex and intimacy. It was understandable, given the environment he'd experienced as a youth, and his tendency to avoid anything that made him feel vulnerable. With plenty of patience and reassurance, Erwin had coaxed Levi into trusting him, and helped dispel his fears about intimacy.

But it turned out Levi had still been holding back. One night, about a year into their relationship, they'd both had a few too many drinks. And Levi had shyly confessed some of his secret desires – including being tied up, spanked, and dominated.

Erwin was hesitant at first, uncomfortable with the idea of hurting or degrading his partner. But as they explored these new activities, and learned both of their limits and tolerances, it only strengthened the bond between them. It had been incredibly satisfying to see Levi slowly open up and explore his needs and desires. And that he trusted Erwin enough to share them with him.

The same night Levi had fully opened up to him, however, Erwin had drunkenly admitted to something he himself had a guilty interest in…

"Do you recall what you told me your secret fantasy is?" Levi probed.

Of course he did.

His confession had been met with a look of panic in Levi's dark eyes, and a long, excruciating silence. Erwin cursed himself for even mentioning it. He quickly explained it was only a fantasy – and he was only interested if they found someone they were both attracted to. But he didn't expect or need it to happen, especially if the prospect didn't appeal to Levi. His partner had seemed extremely relieved about this.

They'd never discussed the topic again.

Until now.

Was Levi suggesting what he thought he was? A wild spark of hope flared in Erwin's chest. It was tempered almost immediately by shame.

"Levi, darling, I told you to forget I ever said that. You're more than enough for me. In fact, you're often too much." He forced a dry chuckle.

Levi's mouth twisted in thought. "So… you're not interested in sleeping with Armin? Or should I say, both of us sleeping with him?"

Guilty memories flashed through his mind, of Armin helping with his office files a few months ago. Erwin had happily gotten distracted from his paperwork by some of their discussions, and even offered Armin some books to borrow when he'd learned of their similar interests. It was a pity the young man was stuck in a role of a general soldier, when his abilities were clearly more suited to academic pursuits.

When the head librarian had approached him asking for an assistant to help her re-organise the library, Erwin gladly agreed. Maintaining their records, and storing fresh materials they'd obtained from newly allied countries, created an urgent need to completely overhaul their current outdated archives system. Armin had been one of the soldiers he'd suggested should apply, because he thought he'd be perfect for the role.

While he kept his interactions with Armin professional, he truly enjoyed spending time with him. There was something intriguing in the way his shy, innocent demeanour melted away when he confidently discussed topics he was passionate about. These different sides of his personality fascinated Erwin.

And yes, he'd indulged in a few forbidden thoughts of what else they could get up to in his office…

Erwin stared at Levi, too shocked to speak, and afraid to voice the truth. But he'd always been honest with his lover, and he wouldn't start lying now.

He sighed, feeling like he was confessing a terrible sin. "Yes, I'm attracted to Armin. But you don't need to worry-"

"He likes you too," Levi interjected, with unmistakable eagerness. "I was curious how he felt about all your cosy little sessions together. So I took the liberty of asking how he feels about you."

Exhilaration battled with dismay inside Erwin. I hope I didn't encourage anything… Have I been too friendly with him, and he got the wrong idea?

But there was a more pressing matter at hand.

"Why would you do that Levi? Did you pressure him into admitting it? Don't you realise how inappropriate it is, for a senior officer to ask such a personal question?"

A crease appeared between Levi's brows. He fidgeted with the frayed armrest on the couch.

"Alright, maybe I could have approached things in a better way. But it was too good an opportunity to miss, given how he already knew about our relationship. And the fact that you already like him."

Erwin drew a deep breath, and finally voiced the question that was simmering in his mind. "Just tell me. Did you invite him to a threesome with us?"

Panic now outweighed his arousal. Even if Armin was interested in him, participating in something like this was complicated, and Erwin had no intention of taking advantage of the younger man. What if he felt pressured into it?

Levi took a sip of his wine before replying, "Yes."

At the worried look from Erwin, he quickly continued, "Look, maybe I did rush things. But if I'd asked you first, you'd have said no, out of some misguided fear I was only doing it to please you. At least this way, I've gauged Armin's interest first. I explained that any potential interaction with you would have to involve me too. And," Levi added with a smirk, "the kid definitely sounds interested. He just needs time to think about it."

Erwin felt a jolt of desire at this news. Don't get too excited, he warned himself. This isn't a definite thing yet. There's still a lot to figure out…

He considered how something as complicated as a threesome would work in reality. What exactly would they do together? How much experience did Armin have? Was Levi truly interested in this too?

If they did set up some sort of temporary arrangement, even as a once-off, they'd need to create rules and conditions, to make sure everyone was comfortable…

Too many questions and potential problems swirled around Erwin's head. He grasped his simplest concern. "He's nineteen. Do you have to keep calling him a kid?"

"Sorry," Levi shrugged. "That's just what I call all the younger soldiers." His face was slipping back into its usual expressionless mask. "I thought you'd be happy about this… I figured after all the things you do for me, this could be something special for you."

"Is this really something you want too?" Erwin asked curiously, reaching out to grasp his partner's hand. "You didn't react well when I first told you about it. Why the sudden interest?"

Levi turned his face away. Was he blushing? "Well, let's just say a threesome with Arlert in particular doesn't sound so bad to me."

"Because you want someone who'd be submissive?" Erwin asked bluntly.

"Partly," Levi admitted. "But I do find him attractive too. He might be one of the weakest soldier I've trained, but he's also one of the most determined. And I admire his intelligence and perception. He's got some spirit too, he's no push-over. And of course he's easy on the eyes. A fact you're undoubtedly aware of."

A thrill rippled through Erwin. His partner's words echoed his own uneasy admiration of Armin. It was oddly exhilarating that they both shared similar sentiments, as strange as the situation was.

Erwin squeezed Levi's hand. "We need to discuss this properly before we even consider it a possibility. Also, I want to talk to Armin, and make it clear he's under no obligation to do this. Maybe we could both talk to him in the next few days?"

"That suits me." A sly glint entered the Captain's gaze. "You know, even if we don't end up playing around with Arlert in person, we can still have some fun with the idea…"

Levi put down his glass, and manoeuvred himself so he was straddling Erwin's lap. Leaning in to his ear, he whispered, "I can't stop thinking about you fucking me, Commander…" His voice was soft and breathless, completely unlike his own.

"Levi," Erwin began, excitement making his pulse pound, "You don't need to pretend to-"

"Armin," Levi corrected impatiently.

Feeling foolish, his face burning, Erwin continued, "I don't think Armin would act like that."

"Well, until we get the real Armin in here, we don't know that for certain. In the meantime, I'm Armin, and I'll decide how I want to behave with my Commander."

Then he swooped down and captured Erwin's mouth in a demanding kiss. Erwin stopped thinking, and allowed himself to sink into the fantasy.

Notes: So turns out I have a kink for characters role-playing as other characters. Not something I read a lot of, but maybe I'll explore it more later on!

I'm new to writing smut and quite self-conscious, what did you think of Armin's threesome teaser? He imagines himself quite passively in his little daydream, but that won't always be the case in the actual threesome. Also, it's no surprise he's got a praise kink! It was fun writing Erwin too, although he's the hardest POV for me to write.

For anyone who's enjoying this story, I update it more frequently over on Archive of Our Own (I'm LauraScofield there too), so you might prefer to follow it there!

I'm also on Twitter at SweetScofield XD

Next Time: Armin gets called to Erwin's office, and it's time to make a decision about the threesome…