Takes place before/after the female titan arc, with the exception that Eren isn't handed over to the Military Police.

(I drew a reference pic including Levi and Eren's wing designs - message me if interested in seeing it. In short, the scapulars are the feathers closest to the shoulder blades, the primaries are the biggest/longest ones closest to the ends of the wings, and the marginal coverts cover the top.)

It all started out with a dare: touch the corporal's wings.

"Have you lost your mind?" Eren hissed under his breath to Jean as they groomed their horses side by side. "As it is, I already give him enough reasons to want to kill me without even trying!"

See, there were rules: unspoken rules that everybody lived by. Absolutely no one touched another person's wings without permission for two main reasons – one, it's insanitary. The oils on one's fingertips would cause gradual damage and ruin the feathers' condition, not to mention additional dirt and grime acquired from other activities. (For this reason alone, Eren quivered simply at the thought of dirtying the wings of the 'clean-freak captain.') Two, wings are hyper-sensitive (especially the scapulars and the tips of the primaries) – and therefore the honors of touching one's wings were usually reserved for a lover in moments of intimacy and ultimate trust.

Jean smirked. "So you're telling me 'humanity's hope' is too weak-willed? What will the civilians think?"

"They'll wonder why 'humanity's hope' was dumb enough to listen to a horse-faced lunatic," Eren muttered in response.

Jean's smirk melted into a frown. "Why the hell do you even call me that? I look nothing like these creatures." He patted his horse's forelock with his knuckles as if to clarify. "Besides – everyone knows he's the only thing you think about more than killing titans."

Eren shot a glare in Jean's direction before determinedly directing his own gaze on his own horse. Of course he thought about Levi – wasn't that to be expected? The corporal had kicked the living shit out of him in front of a public audience to save his life – ironic, but undeniably true. Since then, he hadn't been able to stop thinking about Levi, and some of the thoughts that crossed his mind were enough to surprise him, even scare him.

That particular conversation had transpired a few weeks previously, just after Jean and the rest had been accepted into the Scouting Legion. It had happened before they had encountered the female titan, before Levi had broken his ankle – before things had gone horribly awry.

And yet the dare still lingered on his mind.

After a week of wallowing in self-pity and remorse over failing the mission – grieving wasn't going to bring Petra and the others back – Eren finally formulated a plan: he'd approach Levi and ask for extra flying lessons. After all, despite his training, Eren still had some difficulty controlling his over-sized wings (he still hadn't quite grown into them yet) and perhaps if he could learn from the best, he could spend more time saving others than being saved.

And that's when he remembered Levi's ankle still hadn't fully healed.

"Do I look like I can afford to teach you right now?" the corporal murmured darkly, staring up at Eren from his place behind his desk. From a quick glance, he appeared perfectly fine; he no longer required a cast and could wear his uniform boot again. But after a closer observation, Eren could tell he was still avoiding placing pressure on it and held it at a more delicate angle. His crutch was also propped up in the corner.

Eren ruffled his feathers uncomfortably, the tips of his primaries brushing against the floor. "You wouldn't have to fly with me, sir," he supplied quietly. "Just a few pointers would be fine."

Levi leaned forward, rubbing his sunken eyes tiredly. "Jaeger, look. You may be under my command, but I am not your nanny, nor your teacher. I do not have time to attend to incompetent teenagers."

Eren felt a flare of anger rise in his chest. "Then teach me to be competent!" He balled his fists, his mouth set in a grim line. The further this argument progressed, the less he cared about Jean's dare. "Teach me so that I no longer need to be saved by you, or Mikasa, or anybody. Maybe if you had taught me earlier, you wouldn't be sitting in here, handling paperwork and unable to go on missions!"

Levi's wings twitched. Eren swallowed but refused to be swayed; he was adamant about this now and if provoking Levi was the only way to win, then so be it. At least the corporal couldn't kick him this time.

"It is not my fault that you were unable to learn properly during your three years of training, Jaeger," Levi said in a dangerously soft tone.

Eren breathed evenly through his nose. This man was the one he couldn't stop thinking about? "Our training regimen did not include fighting titans as titans… sir."

"Do you think I was trained for that?"

"You managed to save my life, as well as Mikasa's, without it."

Levi's scowl deepened, but something in his eyes changed. After a lengthy pause and equally lengthy sigh, he sank into his chair, fingertips resting on his temple. "Have it your way, Jaeger. Meet at the edge of Wall Rose closest to the blocked entrance two days from now, dawn."

Eren straightened, hands at his sides. "Yes, sir!"

Eren awoke before dawn on the designated day, sneaking out into the dark with the hope that Levi would stay true to his word. He felt ashamed of his doubt, however, when Levi appeared just as the sun's rays began to peek over the horizon. Eren couldn't help but stare in awe as Levi flared his wings to decelerate, their glossy shine reflecting the sun's pale light. Sleek and compact, they were built for speed and agility and had a wingspan that nearly rivaled Irwin's. Eren suddenly felt self-conscious of his own pair of wings, tucking them tightly behind him.

Levi flapped his wings a couple times as he landed, easing onto his crutch; gusts of air snapped at Eren, stirring his hair into a wild frenzy. He squinted against the wind and blinked away the wetness in his eyes.

"Hanji was disappointed you didn't ask her."

Eren faltered for a moment. "Excuse me?"

"She was more than willing to take my place today. Unlike me, she has all the time in the world for you." Levi approached Eren, regarding him through narrowed eyes. "Pity you don't appreciate her more."

"But I listened to her scientific theories all night once!"

"I've had more than my fair share of titan stories." Levi stopped a couple feet away, sniffing the air. "You bathed this morning, didn't you?"

"Yes, sir."

Levi was silent as he circled around Eren, pausing behind him. "You missed a spot."

The teenager frowned, peering over his shoulder. "What? Where?"

"Your primaries, brat." Eren gasped as he felt hands on his marginal coverts, forcing his wings wide. "You're lazy and let them droop on the floor, and the tips are dirty. Clean them yourself." Levi lingered in place a little longer before removing his hands, as if suddenly remembering the unspoken rule. Eren didn't mind, though; he could still feel exactly where Levi's fingers had made contact with his feathers as if the feeling had been branded into his skin.

"Yes, Corporal," he mumbled as he hastened to obey, shivering at the thought that Levi had touched his wings.

Levi mistook his shivering for a reaction against the cool breeze. "Too cold to continue, Jaeger?"

"No, sir." Eren shook out his wings, satisfied that they were clean enough.

Levi, to no surprise, wasn't. "It'll do."

The corporal continued to lecture him on cleanliness for the next couple minutes – a speech he was all too familiar with as it was frighteningly similar to the one his mother used to give – before moving on to the importance of posture.

"Hover in place," Levi ordered, stepping back to allow Eren adequate room.

Eren nodded, fanning out his wings and beating them in downward, powerful strokes to lift off. When settled in the air, a few yards above the wall, he looked to Levi for approval. He looked even shorter from a higher vantage point, if that was even possible.

"Don't bend your knees too excessively," Levi called. "And ease up on your strokes; aim for more frequently, but lighter."

Eren furrowed his brow. "How so?" If he did that, wouldn't he lose altitude?

"Compensate. Exchange power for frequency."

"I don't see—"

Eren heard Levi heave a loud sigh before the rustling of feathers indicated he, too, had taken to the skies. He stopped once he was even with Eren, his fragile ankle held aloft. "Observe." Eren watched as Levi demonstrated, but the movement of his wings was so mesmerizing, he nearly forgot to pay attention. The corporal was indeed flapping them at a faster rate but made up for it with smaller wingbeats, hovering at a more constant level. "It should eliminate the way you're constantly bobbing up and down like a cork on disturbed water. Do you understand, Jaeger? Jaeger."

Eren started, his wingbeats stuttering slightly. "S-Sorry." He had never been able to examine Levi's wings in action at such a close proximity before – and with no titans to cause distractions, it was all too easy to lose focus on the reason why Eren was here with the corporal in the first place.

Levi fixed Eren with another stare. "Were you even listening?"

"Yes, yes I was," he replied hurriedly, working to alter the rhythm of his wingbeats. "Like this?"

Another lapse of silence; then, "You learn quickly, but I don't have the time to teach it to you twice." Levi exhaled, his expression easing a little. "Is there something on your mind?"

Eren's jaw clenched, but he shook his head.

Another solid stare. "Was it because I touched your wings?"

Eren abruptly thrashed his wings, backing away hastily until there were a few additional yards between them. "N-No! I mean, no, sir! No, I just – well, it was a surprise, no one's really touched my wings before, but I—"

"Calm down," Levi drawled, but there was the tiniest spark of – could that be amusement? – set in his eye. "It has been noted never to touch your wings again, unless we want to lose your concentration entirely." He began to descend back to the wall.

Eren involuntarily followed, eager to correct the misunderstanding. "Ah, corporal, wait—!"

Caught off-guard by Eren's sudden outburst, Levi mistakenly turned to face Eren just as he was about to land. However, by doing so, he misjudged his landing and accidentally transferred his full weight to his injured ankle. Levi let out a cry of pain and his body went rigid, pain paralyzing his nerves as, to Eren's horror, he fell over the side of the wall.

"Corporal!" Seized with panic, Eren dove after Levi, wings plastered flat to his back. Extending his arms, Eren embraced Levi before his wings snapped out, immediately slowing their descent. Air billowed beneath Eren's wings as he glided towards the ground, aiming for a large, shady tree away from passerbys.

Eren, intent on avoiding snapping the corporal's neck with the abrupt change in speed, removed his hand from the back of Levi's neck. Careful not to jostle Levi's ankle further, Eren gingerly came to a stop, folding his wings as he looked down to assess the damage.

"Corporal Levi? I'm so sorry, I shouldn't have called out to you and I hope you'll forgive me. Do you need a doctor? I – what?"

A sense of dread began to fill his chest as Levi started to shake, refusing to meet his eyes.

"Um, corporal? Are you… okay?"

Levi let out an unsteady breath. "H-Hands off…"

Eren's brow creased as he tried to understand, then realized he still had one arm around Levi – his hands resting directly on Levi's scapulars. One of the most – if not the most – sensitive areas of the wing.

"Oh god, I'm so sorry!" Eren exclaimed, throwing both hands up in the air and wings flaring in embarrassment. He stepped back, eyes wide in panic. "I – I didn't mean to, I swear, I–"

"Jaeger!" Levi hissed as he lost balance from Eren's sudden loss of support, crying out again as another spasm of pain wracked his leg.

"Sorry," Eren whimpered, rushing forward to assist. He catches Levi, gently easing him down into a sitting position against the tree. "I apologize, corporal, I – I panicked, and—"

"Yeah, no shit," Levi muttered, his breathing still uneven and pupils dilated.

"I know, it's my fault, I – do you need something? Should I call Commander Irwin, or Hanji? I could go get some medical supplies if you need it, or, or—"

"Eren."

Eren let out a quick breath. "Yes, Levi?" Fuck. "I-I mean… Corporal."

Levi's eyes, clouded with pain, softened. "Just… sit the fuck down."

Eren ducked his head, cheeks burning. "Yes." He sat, facing Levi, wings hunched behind him in shame.

They sat in silence for a few minutes. Levi was leaning his head back against the tree trunk, occasionally closing his eyes and whispering fuck or shit when his ankle throbbed especially painfully.

Eren bit his lip, staring at the grass before him. "Did you re-break it?" he whispered. He had succeeded in completing Jean's dare, but he also had succeeded in fucking up miserably.

"Who knows?" Levi swore again, then tilted his head to look at the sulking teenager. "Eren."

Eren seemed to shrink even further. "Yes?"

"Do you have any idea what that felt like?"

"Painful?" Eren grimaced, finally meeting Levi's eye.

Levi said nothing, then raised a hand to indicate that he wanted Eren to turn around. Biting his lip again, Eren obeyed, wings trembling slightly. "I wasn't talking about my ankle," the corporal said at last. "I was talking about this."

Eren let out an involuntary moan as Levi's hand stroked the length of his scapulars, fingertips soft and soothing. The teenager clasped a hand over his mouth, shocked and ashamed, but he couldn't deny how incredible it felt. Levi's touch was light, almost reverent; Eren shuddered with pleasure, leaning into the corporal's touch.

"I… I had no idea," Eren breathed, glancing shyly over his shoulder. "I… oh."

"Turn around, Eren."

Eren complied and was taken aback to see one of Levi's wings folded in on itself, primaries splayed in front of him. Hesitantly, Eren reached out, then caught himself. "Can I…?"

"Can you?"

"… may I?"

With a single nod, Levi gave his consent.

It was Eren's turn to make Levi moan, and doing so not only gave him a sense of joy, but of power. He may give the corporal headaches and cause for worry and just annoy him in general, but if he could make him melt and go limp with bliss, then it might all be worth it. Maybe he wasn't useless after all.

Levi shifted, twinging his ankle again. He swore, and at that moment Eren saw the opportunity he didn't know he was looking for and took it. Throwing all caution to the wind, he leaned forward to press his lips against Levi's, swallowing the rest of Levi's curses.

"Fucking brat," Levi muttered against Eren's mouth, though his words lacked their usual bite. He sucked on Eren's bottom lip, catching it between his teeth. "Thinking you got lucky with my wings, then taking advantage of me."

"I don't sense much resistance," Eren countered; Levi's cooperation was giving him a confidence boost.

Levi swiped his tongue across Eren's teeth. "Brats like you need to learn gratitude." The corporal pinned Eren's chin between his thumb and pointer finger, forcing the teenager to stop and listen. "Don't think this gets you out of future practices. Once my ankle heals – if ever, by this rate – it won't be this easy."

Eren grinned, feathers ruffling with anticipation. "Yes, Levi."

Levi cuffed him over the side of the head. "Go fetch my crutch."