Commander Erwin Smith never let anybody get too close, it was too dangerous to the emotion barricade he had put into his head to become Commander Erwin Smith, all of this with the accidental exception of Levi. Even though Commander Erwin Smith had thrown his own humanity away to save it as a whole, Erwin Smith still resided underneath the threating glare and the emotionless face he puts on as he returns from an expedition to have mothers screaming at him, asking where their baby was, why he had killed them. Erwin Smith never came out unless he was alone, or with one other person; Levi.
Erwin never showed weakness unless he was with him. He sometimes cried into his should or neck. He would often fall asleep like this, his large body enveloped by the warm arms of the shorter man. Levi never complained, aside from a few mornings when he'd get up with a grunt where his arm had not only fallen asleep, but fallen dead under Erwin's weight.
They both had a silent agreement not to speak of this to anyone, discuss it, or question it. They simply had a routine; Levi would always somehow know when Erwin needed him, he wouldn't even bother knocking when entering the Commander's room, sit on the small sofa on the side of the room, and wait for Erwin to put his pen down, rub his face, hair, or head, and come take a seat beside him. Sometimes it would be a few minutes before he'd put the paperwork down, sometimes an hour or two, but Levi never complained, only sat there, in a silent promise of comfort, reassurance, and trustworthiness unheard of to the world.
That was until today. Levi followed as usual, seeing that Erwin hadn't even touched his evening rations, and instead gave them to the rookie, Sasha, when he felt like no one was looking. He was always wrong, Levi was always keeping at least somewhat of an eye on the man closest to him. He hadn't seen much of Erwin ever since that new kid, the one that might just be humanity's winning deck, Eren, had been assigned to be under his watch practically 24/7. He didn't really mind the kid, Eren amused him even. After all, it was him that volunteered to watch over him, so he couldn't really complain. Tonight, however, Erwin needed him and only him.
Levi rounded a corner and turned to the left, not hesitating a second to open the door, walk across the room and sit on the sofa, one leg over the other. Erwin seemed a bit surprised to see him, but quickly got back to whatever crap he was sorting through at the moment. Levi felt something that he didn't like. He didn't know why, but he refused to let Erwin go over one more casualty report, one more upset or raging letter from families.
Levi abruptly stood from his position and walked behind Erwin's desk, placing his small figure in his lap. Erwin's eyes grew wide as he dropped his pen and stared at the Captain. Levi simply gave him a blank stare, only worries being about ho Erwin HAD stopped reading those hateful, stressful, ugly papers.
"L-Levi, what are you doing?" Erwin's face had a slight red tint and his palms were getting sweaty.

Silent promise broken. Levi had interrupted him, not sat quietly.

"Shut up," Levi groaned and pulled the blonde's neck into a hug. Erwin said nothing, but accepted the hug quite quickly, wrapping his arms around Levi's back. Levi sighed.
"What is this?" He asked in a whisper, his breath on Erwin's neck.

Silent agreement broken. He began a discussion about it.

"What is what?" Erwin replied.
"Don't play stupid," Levi's arms tightened around Erwin's neck.
"I don't know…" Erwin honestly didn't. He felt strongly for Levi in ways a Commander shouldn't for his soldier, but he had so many things going on, he wouldn't be able to have anything with Levi. Humanity's strongest soldier. His little soldier.
"Yes you do. You always know," Levi pulled back looking at Erwin with his usual bored expression, which conflicted with the vulnerability in his voice. Levi hated that he sounded so small.
Erwin paused. "I… I love you, Levi," Erwin had said it. An explosion in Levi's chest went off. He had never felt anything like this before. He hated feeling so dependent, yet he wanted the flame in his chest to be felt by Erwin, so that he could see just how much he returned the feelings.
"But I can't pull a relationship into this mess. Everyone in the walls hate me, I barely have time to sleep, let alone nurture a relationship," Erwin said the words that formed a knife, piercing Levi's chest. Levi looked up to see tears in Erwin's eyes. It sounds odd, but Levi liked seeing Erwin cry, knowing that that side of Erwin was his, no one else's. Not the king who he is sworn to, not the people who know the cold Commander side of him, not his friends who know the more caring side of him. Not Hanji, Mike, Petra, or any of the others had this part of him. Weak, defenseless Erwin was his. His to protect.
"It's a team effort you know? You aren't alone in this. I have Eren to watch out for, a team to lead, and stress to handle. You have so much more riding on your shoulders. Heh, you have humanity taking a free ride on your shoulders, but you have me to hold you up," Levi kissed Erwin's cheek.
Erwin allowed himself to peck Levi's lips softly. What he wasn't expecting was for the black haired male to push his lips up with great force to lock with his own not three seconds later. He smiled sadly into the kiss. He began to cry as Levi lovingly ran his hand's through blonde, now messy, hair. Erwin pulled back as he began to give small sobs which sent his large, broad shoulders jumping.
"Sorry…" Erwin was covering his face. Levi took Erwin's hands and placed them on his own face, kissing his palms tenderly.
"Never apologize for this. Not for crying, not for needing me, not for wanting me. Do you understand?" Levi gave him a stead gaze.
"Yes," Erwin smiled and picked Levi up, earning an agitated grunt from him. He placed him in the bed and wrapped his arms around his waist, kissing his forehead and mumbling something about 'His little soldier…'