Eren panted, struggling to lug himself back to the old castle whilst carrying his 3D manoeuvre gear- which felt distinctly heavier than when he had started his training session four hours ago.

Every muscle screamed in protest as he moved, burning with over-exertion and begging for rest.

Come on, Eren, said his inner voice, spurring him on, not much further now.

He chanced a glance upwards, sighing with relief as the once-distant castle gate loomed above him. He reached a hand out, clasped the gate's edge, and-

"Jaeger!"

Eren snapped to attention so abruptly he swung sideways slightly in momentum. His gear dug into his thigh, making him wince slightly from the discomfort of the hard metal against his throbbing muscles.

He groaned inwardly as the rather small- but inexplicably intimidating- frame of Lance Corporal Levi slunk into view. He surveyed Eren with disinterest as he neared, sharp eyes scanning his form.

"Giving up already?"

"Taking a tactical break, sir."

Levi scoffed, smirking as he brushed past Eren to enter the abandoned castle.

Just as Eren began to relax out of his salute, Levi stopped in his tracks.

"Jaeger," he said slowly, not turning around to face Eren as he spoke. Eren gulped, stiffening in the quickly-thickening air. "Your gear is strapped on the wrong side."

He continued into the castle, disappearing from view.

That would explain the discomfort.

Eren flushed a hundred shades of red as he refastened his holsters.

The rest of his squad had retired to the dining quarters- Eren could hear a low rumble of chatter emanating from the room- and Eren breathed a sigh of relief. He wasn't sure he would be able to look Levi in the face for days to come.

He flushed again as the image of the corporal flashed into his head, but he feared it wasn't the embarrassment of the earlier situation alone that was making the heat rise to his cheeks.

Shaking off the unnerving swooping sensation in both his head and stomach- which he credited entirely to his lack of rest and fluids- he trudged onwards to the basement, where his hard, lumpy bed was seeming more and more like a haven of comfort in his over-exhausted state.

Eren gratefully sheathed the heavy metal gear and uniform when he reached his dimly-lit basement bedroom. He fell into the squeaking mattress, relishing the feeling of clean clothes on his back and lightness in his limbs.

He tried not to think, opting to sink in this newfound sea of rest. He smiled lightly as he was swallowed by a fast-approaching slumber.

Rattle, rattle.

Eren blinked slowly, registering only the gentle flicker of candle-light.

Click.

His body felt unnaturally still, almost suspended.

Click.

He began blinking faster, shocking his consciousness into drive as he realised his wrists were cuffed to the wall just above his headboard. His struggling subsided slightly as he recognised Commander Irvin's voice.

"-not against protocol. It's just intel."

"What if he..." The voice Eren recognised as Levi's trailed off slightly, "fights."

"Don't tell me that speech you made in court was all a lie. You can handle him."

"What happens if he mistakenly retains injury? If those injuries jeopardise the mission?"

"Corporals don't make mistakes, Levi."

Eren listened with bated breath as Irvin's heavy footsteps trailed off and the basement door was clicked shut.

There was a heavy silence that fell into every crevice of the room, and then-

"Do you enjoy eavesdropping?"

Eren gasped and opened his eyes, shocked at the proximity of the voice. Indeed, Levi was crouched on the floor just beside the bed, charcoal eyes boring into Eren's green.

"Or do you just like the sound of my voice?"

Eren tried to force back a blush, not liking how much Levi's downright purr was affecting him. His lower-stomach swirled, forcing him to shuffle slightly to ease the sensation.

"I'll take that as a yes."

"If you don't mind me asking, Corporal, I-"

"Want to know why I'm here?"

Eren nodded.

Levi didn't answer and, standing up abruptly, reached down to retrieve a blade. He looked at Eren, and Eren could see unmistakable guilt in the older man's eyes.

"We need to see if pain is a trigger for your transformation. We can't have you turning at any moment during a mission, or during training. I don't need to tell you why."

Eren's insides dropped with a guilt so heavy he thought he would sink through the mattress.

"Anyway," Levi started, snapping Eren out of his thoughts, "it was Irvin's brilliant idea to strap you down and probe you a bit."

"You're going to torture me?"

Levi averted his gaze.

"Get it over with."

"Jaeger-"

"Please!" Eren exclaimed, jerking upright. The chains that bound his hands and legs rattled noisily. "If that's the only way, then please, just do it!"

Levi bent down and leant over the Eren so that the tips of his hair tickled Eren's rapidly colouring cheeks.

"Now that's the soldier I want in my squad."

Eren's pulse quickened, his chest swelling with a glowing pride. The feeling acted as a force field for the following onslaught of cuts, jabs and careful incisions made to his body- which soon began to shake with the adrenalin of intense pain.

It seemed the night would never end.

Every second trickled slowly by, aided by the soundtrack of his occasional grunts and yelps, and a constant, harsh breathing that echoed though the basement.

The younger soldier couldn't help but notice the furrowing of Levi's brows, or the discomfort with which Levi seemed to hold his blade.

He couldn't help but wonder if this was hurting Levi more than it was hurting him.

When Levi finally declared the session over, Eren collapsed back onto the bed, sweat and blood darkening the sheets.

"No threat here," Levi said, reaching over to unlock the too-tight cuffs. "Irvin better be satisfied with his little experiment."

"I thought you liked inducing pain, corporal." Eren murmured in his stupor.

"As punishment, there's nothing better. Not this. Never this."

Levi rubbed the dark bruises on Eren's wrists.

"You're more sensitive than you let on."

"There's no room to let on sensitivity in this line of work. Not when your best friends are a dual blade and some gas."

Eren smiled sadly.

"You know the price of weakness," Levi continued, gently referencing Eren's losses. He had let go of Eren's wrist, and was slowly running his calloused fingers down the already-sealed scars on Eren's bare torso.

"In this world, you fight," Eren said, stronger this time, "or you lose."

"Lose meaning-"

"You die."

Eren sat up slightly, staring Levi in the face.

"One fuck-up. One. That's all it takes," Eren's bright eyes glazed, the orange hue of candle-light reflected in the suspended tears. "And your whole world can cave in right before your eyes. Before you know it, you're standing in the rubble of what used to be your life, trying to-"

"Put back the pieces," Levi said solemnly.

Eren blushed at the intensity of Levi's gaze. He realised that he had subconsciously taken hold of Levi's hand, and was clutching it like it held all the answers to all the suffering.

"Help me," said Eren quietly, his voice cracking.

Levi wove his fingers between Eren's as he assuredly closed the- rather small- gap between them. His lips were met with no resistance, and the two shifted closer together as they kissed, chastely and slowly, as if they were both wading into untested waters.

Levi's other hand wound its way into Eren's rich, brown hair, taking fistfuls as he leant further and further into the kiss. Eren leant back onto the bed, groaning as his lips were parted by Levi's searching tongue. The two struggled to breathe as they embraced, reluctant to surface from their own wanton desires for the annoying necessity of air.

Eren hissed as Levi's wicked lips trailed feather-light kisses down his jugular, his collarbones, his chest.

He cried out at Levi's tongue swirling around his nipple, shocked by the intensity of the sensation.

The corporal shrugged out of his top-half of clothing and leant his training-hardened body down onto Eren again, grinding groin against groin in pure need. Eren wrapped his legs around Levi's back, mewling as Levi's mouth reached his neck again.

"Like this, baby?" Levi asked, his voice husky.

He bit down, hard, on Eren's throat.

"Ah! Corporal!"

"I love how vocal you are, Jaeger..." Purred Levi, advancing down Eren's squirming body.

He tore off the rest of the boy's clothing to reveal Eren's painfully-hard erection. "You've never been able to control that mouth of yours."

Levi lifted the member to his lips, and whispered: "Now scream."

He descended upon the engorged member, taking the entire length so that his lips pressed against Eren's torso. He hummed gently, sending vibrations directly from the pit of his throat to the hyper-sensitive tip of Eren's cock.

Fuck, did Eren scream.

"Oh, god. More, more, more!"

Levi bobbed his head furiously and was almost gagging as he swallowed up Eren's length. He kept his eyes locked onto Eren, basking in how the smaller boy's features would contort in sheer pleasure.

"I can't, corporal, I'm going to-"

"No you're not, baby. Not till I say you can."

Levi 'popped' off of Eren's erection just before he could hit climax. He unbuttoned his trousers, releasing his own manhood. He stroked the long member a few times until it was slick with pre-cum, and then positioned the tip right at Eren's quivering, convulsing, entrance.

"If that experiment was good for one thing," Levi growled, kissing up the shell of Eren's ear, "it told me you can handle a bit of pain."

He thrust his entire length into Eren's heat, hissing at the sheer, iron-hot pressure clamping down on him.

"You're so tight, baby," He whispered, eyes rolling. "So fucking tight."

"Please, please, move!"

Levi needed no persuasion. He pushed into Eren's heat again and again, finding his prostate immediately and abusing it thrust after thrust.

"Say my name..."

Levi took Eren's cock in hand and timed his strokes with his thrusts, which were becoming more and more shallow and he reached a fever-pitch.

"Corporal!"

"My name, Jaegar!"

"LEVI!"

Eren jerked roughly in Levi's hold as he screamed, releasing himself in long streams of white across their chests.

"Jesus, Eren!"

Levi cried out as Eren's muscles clamped down- hard- on his length. He came inside the boy, pumping Eren full so that some of the sticky substance dribbled of his ass and onto the already beyond-usable sheets.

The two slumped into each other's embrace, Levi pulling out and lifting the boy onto his chest as they lay down to sleep off their intense orgasms.

"Corporal?" came Eren's drowsy voice.

Levi 'mmm'ed' in response.

"Instead of putting back the pieces," Levi stroked Eren's sweat-drenched hair, "lets just lay down in the rubble."

"And do what...?" Mumbled Levi, struggling to fight off sleep.

"Thank our lucky stars that we're not laying down alone."