Eren is a learner. Things don't come to him easily, he doesn't just get stuff right like Mikasa or have stores of knowledge like Armin. And now he's in a new squad with new people, and most importantly Captain Levi whom he doesn't quite know what to do with – so he watches, and he learns.

He sees that despite the recent beating that he can still sort of feel if he thinks about it, there might not be a reason to truly fear Levi, because nobody else does. They stand straighter when he comes close, true, but they smile as they do it. They look proud when Levi nods at them.

Eren learns during training that "do it again" means "good", and that a short nod means outstanding excellence. Silence is acceptable, and mistakes will be reprimanded with blunt explanations as to what was done wrong. Levi will stand close, then, glowering, his full attention on the hapless soldier getting a scolding, and analyze what went wrong until the soldier proves themselves capable of doing it right.

It happened to Eren once, as he was forced, squirming with embarrassment, to listen to a tirade about how he was holding the blades wrong, releasing hooks at the wrong time and wrong angle – but when Eren tried again, he realized that understanding what was wrong made it possible for him to do it right. He earned a nod and a curt 'do it again', and later found himself standing straighter and saluting with a proud smile on his face, same as the others.

Eren learns from Petra how Levi likes his tea, from Gunter how to launder clothes properly, proper floor washing technique from Auruo, and from Erd, the tone of voice to use when you wanted something from Levi.

From all of them, he learns that the captain is not to be touched.

Of course, it makes sense, Eren thinks, and becomes as careful as they are. He passes things to Levi with only the barest meeting of fingers, and is careful to avoid his clothes and rubbing shoulders with him in the corridor. Dinner is easy, as Levi sits at the head of the table and won't be brushed against, but any other time, Eren knows to leave at least ten centimeters distance.

The fact that the captain asks for none of it makes Eren try all the harder.

Eren never questions the things he's learned, because they make life in the castle smooth and easy, until one night. He's finished his chores and it's not yet time to sleep, so he's sitting in one of the small downstairs rooms because it's heated and set up with all the sofas they found that were in decent repair. The room is cozy and the light is good, so Eren's perched on the softest couch, which is placed against the wall directly under a lamp. It's a favorite place for reading, but right now Eren is mending the sleeve on his uniform.

The door opens and closes with only the slightest creak, and it takes Eren a few seconds to look up and see who it is because he wants to finish the row. The sofa beside him sinks and Eren glances out of the corner of his eye and then jumps because it's the captain.

The captain doesn't say anything, just nods a small greeting at Eren before opening the book he's brought. Of course he would sit here, Eren thinks, it's the most comfortable and the light is the best – but the sofa is small, forcing their thighs to touch and their elbows to rub together, so now Eren is invading the proscribed ten centimeters.

Hurriedly, he ties off the stitch and stands.

"You-" the captain says, then stops.

"Can I do something for you?" Eren asks, eager to prove himself. Levi's expression certainly says he's not pleased, another thing Eren has learned to recognize during his time with the squad.

Levi shifts on the sofa, scoots further towards the other arm, then flicks his eyes at the empty space. "You don't have to leave," he says.

Eren stands and stares, at that empty spot and at his captain, and doesn't know what to think. He must have stared too long, because Levi clears his throat and opens his book pointedly, hunching over it.

"That wasn't an order," he said. "You can do whatever you want. You don't have to stay. Go take a shit or something."

Levi never asks for things, Eren thinks, but you'd have to be an idiot not to understand that one. So he smiles sunnily and strolls back over, flops down on the sofa next to his captain. They're pressed together now, thigh to thigh and so close that Levi can't turn pages without brushing Eren. So close that Eren can feel how relaxed Levi is against him. He's warm, Eren thinks, and very human, and maybe everybody is wrong. Maybe Levi doesn't want to keep a ten centimeter wall of nothing between him and the world.

Eren's a learner. So he doesn't move away, not even when Levi falls asleep and his dark head droops against Eren's shoulder, but instead shifts around so he'll be more comfortable, and wraps his right arm carefully around his captain's shoulders.

When Levi doesn't object, just sighs and leans closer, Eren learns that everybody else is wrong. Their captain loves being touched.