Armin was conflicted. They were superior and subordinate after all, kept apart by rules and regulations and just plain common sense. It was wrong. He was more than twice his age. But the heart wants what it wants, and it wasn't like there was much else that made Eren smile lately.
Armin noticed before Eren himself probably had, the way his eyes would follow Levi around the room. Of course he'd notice; he'd picked up on all sorts of things like that and he'd been watching his fellow cadets fall in and out of crush with each other for years. He never talked about what he knew, or about his own futile affections; he was pretty sure no one would get it if he did.
His crush was on Erwin. Bold, ruthless, brilliant, Erwin.
For a while Armin had been rather charmed by Eren's infatuation; it was just something else he had in common with his best friend, after all, and when he felt mopey (although he never said why) Armin could sit with him and say that he understood. Eren never noticed his wandering eyes; for a start he took several long weeks before Armin was even sure he'd realised his own feelings.
They could be hopelessly love-struck for unobtainable superiors together then, and frankly it seemed like the safest way to be given the odds any one of them would still be alive this time next year.
And then, something changed. It took Armin a while to notice, because Levi was very hard to read and was most certainly hiding his own feelings, but he looked after Eren. Not just physically, but he did his best, quietly, to make sure he was okay. And when he saw the three of them talking together, Levi would sometimes smile. The first time he noticed this, Armin's stomach lurched. He'd never considered the possibility that it would actually go somewhere.
Armin watched them grow closer, inch by inch. It was wrong, he told himself, but he knew it was envy rather than any real attachment to the rules that bubbled up in his heart. If Eren could receive soft smiles and quiet words, why couldn't he?
There were books at HQ. The first books Armin had acquired access to in years, and he spent every spare minute dusting them off and looking through them. Technically he was out past curfew, but as long as he didn't push it too late he could get away with it. He was heading back to the barracks, trying to remember who was rostered on patrol that night when he heard voices from the mess.
He poked his head around the door and saw Eren and Levi, talking. They were sitting in their usual places; Levi at the head of the table, Eren on his left but they'd dragged their chairs closer. They had tea cups forgotten in front of them, and they leaned in towards each other to talk.
Levi chuckled and shook his head and Eren said something and lightly touched his arm. It looked like summer over there. Neither of them had noticed him and he stepped back into the hallway. He couldn't see Levi's face but he could see Eren's, and the expression made his heart hurt. There were things he couldn't share with his childhood friend, and he'd always known they'd be coming, but now, already? But he looked so brilliantly happy, Armin couldn't resent him for it.
Armin put his back to the stone wall and sagged against it. He didn't want to see this.
He turned to go, find another route back even if he had to climb out a window to do it. He could not walk through that room.
“Promise me you'll at least try and sleep, Hange.” Armin was hurrying back along the corridor when he heard Erwin's voice, followed by the sound of a door closing and footsteps. Shit. If he was heading to the kitchen for a late night cup of tea he was going to walk right in to Eren and Levi's little meeting, and Armin was quite sure their commander would be sharp enough to know what sort of meeting it was.
Armin figured he had three options: one, climb out a window, head back to the barracks and pretend he was never there, two: clump back to the mess as loudly as he could giving Eren and Levi time to separate, or three: run interference with Erwin and let them do their thing a while longer.
It was no contest, really; the third option gave him some time with Erwin, even if all he got out of it was a dressing-down for being out after curfew.
He straightened his spine and kept walking.
“Armin,” Erwin was carrying two empty cups, presumably taking them back to the kitchen from Hange's lab.
“Good evening, sir.” Armin saluted.
“You're up late,” he said, and the way he said it clearly required some sort of explanation for this fact. He wasn't going to chip him just yet. He trusted that Armin had reasons for the things he did to a certain extent.
Armin thought back to Eren and Levi and his resolve wavered. Maybe he should try and stop this before it went too far. He didn't know. Erwin might have some advice, if he kept it general.
“Actually, I was looking for you, sir.” In the last thirty seconds, it was true, but it wasn't a lie. “I need advice.” He lowered his hand.
Erwin cast about and eventually put the cups on a nearby windowsill. “All right, Armin, I'll do my best.”
“Right.” Deep breath. “The rules about fraternisation are pretty clear, in theory. But I suppose I was wondering how they're applied in practice in the Survey Corps.”
Erwin blinked at him. “Oh. Oh that sort of advice.” He shrugged, a bit helplessly. “I'm not really sure I'm the right person to approach.” He thought about this for a few moments, running through the other possibilities in his head. “Well, I suppose you could have done worse. Armin, look, we know you're young and under a lot of stress, and we also know rules are almost impossible to enforce. Basically, don't get caught and we don't want to know about it.”
“No, I didn't mean among recruits, Sir. I meant.” He looked up into Erwin's eyes, “Between a recruit and an officer, sir. I know it seems really wrong, but if they both understood the limitations of of their roles and obviously tried not to get caught.” He recalled Eren's expression, and Levi's soft laugh and found himself mounting a defence rather than asking a question. “Being happy for a little while, because they could both use some of that, I think.” He smiled, hopefully.
The colour seemed to have drained from Erwin's face. He tried to say something and then sighed and leant against the wall. “Oh, Armin.”
No. Wait. He'd completely got the wrong idea. Oh shit. That wasn't what Armin had meant at all and his face felt like it was on fire. He drew breath to explain, to out Eren and Levi if need be but the words died in his throat when Erwin lifted a hand and brushed his cheek.
“I tried to hide it,” Erwin muttered.
“You did a good job; I had no idea,” Armin heard himself saying. He could hear his own heartbeat.
“Brave, aren't you then?”
“No, I completely-” He forgot what he was going to say when Erwin's finger curled under his chin, tilting his face up.
“What's one more sin?” Erwin murmured, and bent down to brush his lips against Armin's. It wasn't his first kiss, as both Mikasa and Eren had kissed him before, but it felt like it. It felt like something had been torn away when Erwin straightened up again. Armin chased it. He stepped forward and put his hands on either side of Erwin's face, and popped up on his toes and chased it, hungry.
Erwin let himself be captured. Armin could feel his ambivalence, the way he still held himself back, and Armin didn't push it for now, braving a taste of his lips but no further. Erwin wrapped his arms around him and Armin sank into his warmth. It was too new, too exhilarating to feel like coming home, but it still was a wonderful place to be.
“What?” Erwin asked.
“You know, I wasn't actually talking about us, earlier.”
He looked up to see Erwin frown. “Then?” His expression cleared and his lips thinned, “Oh, I see. That half-pint little deviant. He knows the rules-”
He released Armin and made to leave and Armin grabbed his arm.
“Erwin!” He gave him a look. “That's a bit hypocritical, don't you think?”
Erwin hesitated. “Where are they?”
“In the mess.”
“I suppose they can't get up to much there.” He relaxed and Armin did too. “Do you want to?” He looked at Armin uncertainly, “Oh, I don't know, go back to the library for a while?” He asked like he half-expected Armin would turn him down.
“I would really like that.” He didn't let go of Erwin's arm, and Erwin didn't shake him off.
The next time Armin saw Levi, they were saddling up for more training. He jumped when the Captain put a hand on his shoulder.
“Not bad, Armin. Not bad.”
Armin smiled. “Thank you, sir.”
“But tell our fearless leader not to leave dirty cups in weird places next time.”