Levi was never one to break character, or at least Erwin liked to believe.
The shorter man was so strict even with himself. Not a smile was given, nor a laugh. Not even much acknowledgment was given to fellow soldiers. It was an aggravating thing to witness because, albeit he was loyal, Levi was a tough one to crack.
And Erwin strove to be the one to crack him.
The nights when he would seduce Levi to bed were the best. Now, normally Levi would be the one forcing Erwin into bed, ushering him into the room with nothing more than a few presses to the chest and a lustful gaze.
But when it was the other way around? Levi didn't like that. His little sliver of dominance would be squashed by Erwin's kisses. Kisses to the neck, the jaw, everywhere their height difference would allow. And it was only when Erwin was the one getting him into bed that Levi denied any express of desire towards the elder out of spite. So the commander built the habit of waiting patiently until he knew he'd be the one in command.
When Levi didn't get his way, he'd often retaliate by holding back as much as he could during sex. Like a child pouting over not getting that toy they wanted, Levi pouted over his lack of dominance.
He'd lay on his back, acting out as much as he could by providing as little as he could. Narrowed eyes fiercely glared up at the ceiling as his lover sought out a steady pace. It was a sight to behold; a clearly flustered, angry little Levi soaked in sweat and flushed a beautiful red. While it was a sight worth ravishing, Erwin held back.
He'd take his time to break the smaller of the two.
The silent treatment went on for a while, usually. Levi would never break his glare pointed towards the ceiling, nor make a sound by trapping every single one in his lungs.
Then Erwin would pick the pace up, strong hands pushing the captain's legs up by the thighs until they hovered over his torso.
Only by this point would Levi's lower half begin to tremble, brows knitting together when the continuous friction proved to be too much. He'd bite his lip until the smooth skin split and, oh, it was so nice to see. He was on his way to cracking.
And soon enough, when Erwin began to give his thrusts a little more aim to seek out that one upper hand hidden within his tinier lover, Levi would make the quietest of noises. Little mewls, muffled by the lips he kept clamped together. His eyes would become half-lidded, then fully covered while his head craned back. Thin fingers clawed into the bedsheets, already damp with the sweat of the conjoined bodies, tugging the blanket up between the clenched digits.
The ending was the sweetest to watch, when Levi finally broke. First, his lips would split apart in a desperate gasp. His back would arch in, hands flying up to grip the blond's shaped biceps to dig his nails into them. Erwin would lower himself, positioning the lithe legs around his waist and allowing Levi's arms to go around his torso in a vice of an embrace.
Erwin didn't mind the scratches being etched into his back, really. They always stood for a job well done.
And hearing the captain, ever so stoic, exhaling his name so brokenly, so vividly with every beat, was more worth it than he could imagine.
The two bodies would writhe against each other in their final moments of orgasm; Levi continuously moaning out the blond's name in a decrescendo of tired gasps, Erwin never ceasing to buck his hips into the others until the delicious friction was gone.
"I hate you," Levi would always mumble afterwards, even as he entangled himself with the bigger body after cleaning up.
"I love you," Erwin always replied in that rough, sleepy tone of his, lips nuzzling the angry, smaller man's temple until his body would eventually relax into the embrace.
For a little while afterwards, the blond would merely watch him sleep. While his muscles would begin to cramp from being in the same position for too long, he didn't dare move. No, Levi would need the rest to recuperate and rebuild himself.
Erwin would never dream of disrupting the process.
Because he just loved getting to break the man all over again.