This was written based on a writing prompt I recieved on Tumblr.

Reach

Eren was used to reaching things for the Captain, albeit discreetly. The time Oluo had deliberately put the coffee cups beyond reach, or when the approval paperwork for cleaning materials were suddenly stored on the top shelf by Erwin, or when someone had thought it funny to store his 3D Manoeuvre Gear on a wall mount just out of his reach. No one had owned up to that one yet.

Eren would watch as Levi reached for the item, came up short and would glance around to ensure no one was witnessing his failure. That was when Eren's glance would snap away to anything else he could pretend to find interest in. This had been unfortunate once when he had accidentally acted too enthusiastic about one of Hanji's experiments and had suffered an uncomfortable afternoon with her examining his tongue and asking questions which he simply couldn't answer when in such a once Levi was satisfied no one had seen him (or was at least satisfied they were pretending not to) he would swear and walk off. Sometimes just to the opposite side of the room but more often than not he would leave to pace for a minute or two in the hallway before returning.

That was usually when Eren would retrieve the item and leave it on a lower shelf or the table, somewhere accessible. Sometimes he would remove other things too, to make it look like he'd been looking for something himself. Just in case he got caught. He was not sure how the Captain would react if he ever walked in as Eren was retrieving something for him. He was a proud man after all, even if he sometimes pretended he wasn't.

And so when he had walked in to see Levi stretching on tip toes to reach the top of the window pane, kitted out in cleaning apparel and a damp rag in hand, it had only been natural to pretend to be looking for something on the table until Levi let out a few curse words, slammed the rag down (as best as a rag could be slammed) and stormed off.

The second he was gone, Eren grabbed up the rag and went to the window. He might not be able to bring the window down to the Captain but he could still take care of his frustration at how dirty it was. Not that Eren could see a single mark on it himself of he had decided to do this and so he used the rag to scrub at the top of the pane around the point that Levi would have started to struggle. He put more effort in than he probably needed to since it already looked crystal clear. He couldn't even see a difference between the top and where Levi had already he was satisfied he had cleaned the whole section of the pane Levi couldn't reach (having to stand on his tip toes himself at one point), he wiped the sweat from his forehead against his arm and turned to put the rag down. That was when his heart jumped into his throat as if it was using some form of 3D Manoeuvre Gear made for internal organs.

Captain Levi was standing in the doorway watching him. In fact he was leaning against the doorway so he had probably been there for a while. Eren could feel the sweat on his forehead dripping again but this time it felt ice cold and chilled him. It was difficult to tell how Levi felt about what he was doing since the Captain never showed much expression at anything normally anyway. His brow was slightly furrowed though so it was probably safe to assume he was angry with him. Eren swallowed painfully.

"Uh…Captain! I was…I just…"

"That's a piss poor excuse for a polished window," Levi spat at him in his usual frightening tone. His eyes had turned dark and Eren watched as he moved towards the window quickly. He glared at it as if it had personally taken a dump on his desk and told him to clean it up.

"It's filthy. Redo it," he demanded and Eren immediately jumped to the task, scrubbing with the rag until his hands began to cramp from the effort. He glanced back at Levi who had crossed his arms and had graduated from glaring at the window to positively scowling at it.

"You're making it even worse somehow," he told him before dropping his arms and sighing as if resigning himself to something. He flicked his glance from the window to Eren."Kneel down," he said his eyes flicking down towards the ground to make his point.

"What?" Eren said stupidly, not following his train of thought. Why would he need to kneel?

"Are you deaf brat? I said kneel down. Now."

"Uh, yes sir!" Eren exclaimed placing one fist over his heart and the other behind his back in the Survey Corps salute briefly before dropping to his knees where he stood.

Eren was astonished when Levi used the change in his height to climb onto his shoulders. He tensed more than he thought a human body possible and briefly wondered if it was possible for his muscles to snap under this much tension. He placed his hands atop the Captain's thighs to hold them in place either side of his head.

"Up," Levi commanded and he painfully gripped onto the hair on top of Eren's head for balance while he clumsily rose as quickly as he dared. He was absolutely terrified of what should happen if he tripped and dropped his commanding officer and desperately tried not to dwell on it. Once he was upright, Levi let go of him and reached his hand down for the damp rag. Eren let go of one of his legs to pick it up from the table and passed it up to him before replacing his hand again and moving closer to the window.

Levi was much heavier than he looked and they made slow progress as Eren stumbled every time the weight atop him shifted. Levi always responded by slapping the top of Eren's head like he was a disobedient animal of some kind but never uttered a word. In response Eren would simply blush, embarrassed by every detail of his situation.

It was an excruciating hour before Levi finally decided the window was his standard of clean and told Eren to kneel down again. Once Levi had climbed off of him, Eren found he didn't want to stand again and instead slumped backwards to sit down. He was glad no one had seen him being used as a makeshift ladder as they were bound to make fun of him for it and since Levi would feel no embarrassment from it, he would be completely on his own in his mortification. His eyes drooped with his mental and physical exhaustion.

Just as he was considering how long he could conceivably stay sitting on the floor like he was, he heard the Captain shout to him from, the doorway.

"Oi! Brat! Don't just sit there! There's a whole floor full of windows to clean yet."