It seemed that fate was destined to overcompensate for Eren's needs in life. Need to exact revenge on titans? Become one yourself. Procreation? Here's a giant cock, hope your partner has fun with that, ha ha.
At least this is what Levi concluded when he—humanity's finest soldier and witness to countless horrors—came face to face with one of the most impressive, if not terrifying, feats of nature.
"W-what's wrong?" Eren asked anxiously. "Is it…" He faltered, face reddening. "Is it too small?"
Levi could've choked(he clearly was going to, sooner or later). Hanji would've dubbed it a magnificent and possibly sentient being. It was obvious Eren had never seen a cock other than his own, and suddenly Levi wasn't sure if he wanted the burden of Eren's virginity.
"It's fine," he muttered, pumping the monstrosity in his hands and questioning his own sense of self-preservation. Thank god Levi was unparalleled when it came to keeping his cool. A lesser man would've long fled the room in devastated terror.
He licked at the head, relieved to find that it at least tasted like a cock, before sealing his lips to the shaft, suckling across the underside and down to the base.
Listless eyes flickered upward to find a panicked Eren. He hummed in inquiry against the heavy cock as he made his way back up. "Come on now, don't tell me you don't know how this works."
"O-of course I do!" Eren flared. "It's just that—a-ah!" Levi had slid his mouth over the head and was swallowing him—until two inches down, his jaw decided that it had opened as wide as it was capable of.
Well, this is no good. Though, judging from the moan that had rolled from Eren's throat, it was evidently very good. "C-corporal, wait," Eren managed, in broken syllables.
"Yea?" Levi pulled off with a light smack, tonguing the slit of Eren's cock to capture the leaking precum.
Eren looked flustered as he answered, "I wanna try it, too."
Slowly, carefully, he rubbed Levi's arousal through the fabric of his pants. Even as he unzipped and peeled off the pants, palming the bare cock in his hands, there was a delicate reverence to his movements. Almost timidly, he kissed the tip of the corporal's erection, and nothing could've prepared Levi for the way Eren swallowed him in one fearless maneuver.
F-fucking hell, the kid was bold, and gifted with instinct if not wit. It wasn't long before Eren found the right balance of suck and lick, working a rhythm that Levi seemed to be responding to, breaths growing exceedingly ragged as he watched the length of his cock disappear between those hot lips over and over again.
"Fingers," Levi demanded, hoping there wouldn't be a need to pause for instructions. Luckily, Eren caught on. He took a moment to wet two fingers, rubbed at Eren's entrance as he returned to sucking him, and slowly slid one finger in, then two.
In and out, he pumped, and he could feel how Levi tightened and clenched hard around them. The sight of a writhing corporal spurred Eren on, Levi's usual expression of indifference twisted into something akin to tortured agony, beautiful. It was with a firm nudge that Levi shoved Eren off and tugged him up with frightening strength, kissing him hard, and Eren met him hot and yielding.
His lips were salty, his tongue pliant and willing as Levi probed and plundered the depths of his mouth. He could feel the way their cocks slid and rubbed against one another, the way Eren ground down on him, the subtle way he shifted, positioning himself at Levi's rear, and pushed.
"Woawaitaminute—!" Levi protested sharply into the kiss.
"Corporal, I…I can't. You're so…mnn, tight."
"Fucking—." Levi voice grew strained as Eren stretched him further and further, nudging deeper into him. "You are…nnh, never topping a-ah, again," He said hoarsely. Certainly Irvin would have enough sense to report that Levi had officially passed in combat at the hands of a titan, not in a bed by Eren's monster cock. The thought was depressing.
What felt like centuries of pain later—though it was only a mere two minutes that Eren lasted—Eren collapsed on Levi's chest in a complete state of euphoria, cock still pulsing within Levi.
Yea. Never again.
"So how was it?" Levi cursed her chipper tone. Nothing, including the limp he so painfully concealed, ever slipped Hanji's keen notice.
He contemplated. "Like taking a massive shit you've held in for weeks."
She never quite understood why Levi insisted on his fecal references, but it was enough to paint a very vivid, if not disturbing, image.