A/N: I really, really wanted to do some public Eren/Annie smut and Eren being a smug bastard about making Annie squirm. I'm so sorry.

The detailed diagram of the inner 3DMG mechanics is sketched out to fill the board, scaled to include intricate gears or overviews in the simplest form, and it appears that their instructor is rather proud of himself for his work because he's in a particularly giddy mood. Despite her best attempt to take the same notes as most of her class, Annie's fingers are clutching the edge of the desk instead of her quill, and she's focused on keeping her hitched breaths steady to avoid the possible attraction of the other trainees.

She's trying to pay attention to the lesson, she really is. But of course Eren Jaeger has other plans.

They're in the very back row in the two right seats closest to the wall, the farthest away from the front either of them has ever been. Eren has his chin recumbent on one fist, his other hand situated beneath the shared desk top. To the instructor, it appears he's just casually observing the diagram with one arm on his lap, but to Annie he has never been so distracting.

She keeps her head reclined so no one can see her face and she pushes her back against the chair, hips forward, legs parted. His deftly fingers stroke her labia, the underside of his middle finger's knuckle pressing roughly up against her swelling clit, rolling over it on the returning down stroke. He even humors her by running the tip of his finger around the circumference of her entrance, earning a shaky exhale of breath from her that she muffles with the back of her hand.

"The release of gas forces these axillary gears to move faster…"

This sounds important, really. But the instructor's voice keeps fading as a tingle in her spine creeps into her brain, numbing her ability to focus on anything other than what Eren's doing to her. She can safely say he's working her straight into submission and she won't do a damn thing about it because holy Sina is he good.

He sets a steady tempo, interrupting every few strokes to circle her clit until she's nearly bucking her hips, and he returns to his gentle caresses. Or he'll prod her entrance eagerly, outlining her rings of muscles. She keeps her head inclined to avoid making eye contact with anyone, especially the instructor when he turns to face his class, and she crosses her arms, concealing her fingers clutching her nipples through her sweatshirt to help her towards her release.

"…have a removable compartment to allow the application of a lubricant, which keeps them from whittling each other down…"

This is really, really important. Or maybe she's just telling herself that.

He picks up his pace, the friction between them sending her nerves haywire as her clit throbs against his captivating touch and her muscles tense with every stroke. She covers her mouth with the thick of her sleeve to silence her pants, reaching down with the other hand to grasp his wrist, coaxing him to apply more pressure. Her hips begin to rock, even as she struggles to keep her body from shifting too much and selling her out to their whole class (she wouldn't live it down knowing them).

She expects to release soon, but he suddenly stops, his slender fingers hovering delicately over her entrance. "You're really wet," he whispers quietly, and she flushes, drawing her hand away from his to lift her hood up over her head.

"Shut up," she hisses, barely audible with her head pointed down. "Just get on with it before I switch seats with someone."

He strokes her again before sliding his first digit into her velvet warmth, massaging her side walls to coax her open and pressing up against her front to earn a pant she has to muffle with her sleeve again. She leans back in her seat completely now, legs parting until she's touching the wall and his knee. Despite her best attempt at trying to avoid drawing any unwanted attention she's on the verge of letting a cry escape her throat.

He pulls back out to stroke her clit. The second time he meets her warmth he gently pushes in his two middle fingers, gradually settling deep within her. Her chest hitches, sleeve still effectively silencing her, and when she adjusts he begins to move, working in and out, his palm roughly stroking her throbbing bundle of nerves.

"…the release levers can get jammed here, and here…"

Trying to appear like she's paying attention isn't happening, and if anything, she looks like she's distressed.

"…but can be fixed, quite simply, by knocking on the marking here, which realigns the axis…"

She really wants to pay attention.

On his next backstroke he pushes up harder, earning an acute jerk from her eager hips. A barely audible whimper emits from her throat. Mikasa, sitting beside Armin on the left side several rows down, turn her curious gazes up to them. Annie appears tense, maybe even sick by the way she's covering her mouth, but Eren doesn't seem concerned.

Wait. The Eurasian squints. Why is Annie's face so…red? Is she embarrassed? Does she have a fever?

Eren catches her gaze and points to the board. Pay attention, his gesture reads, and she furrows her brow at him. A moment later she turns away. Annie would probably deny any inquiries directed at her condition regardless, so Mikasa shouldn't bother worrying.

When he's sure that no one's distracted by them he shifts his pace into a hard, slow thrust that pushes against her inner nerves. Her walls constrict his fingers, pulling him into her insistently, and in response she grasps the edge of her seat with her free hand. His forearm burns immensely with effort, threatening to give him carpel tunnel if he tests beyond his limits, but knowing that he has her squirming in pleasure convinces him to bear through the pain; she suddenly tenses in her thighs, the obvious quivering in her womanhood a sign that she's hit her climax.

Her entire body stiffens. Fuck. She can't.

And she jerks, the orgasm shattering its way through her veins, exploding like brief bursts of lightning. She moans as she comes, her muscles coiling and unwinding one wave of pleasure after another, and suddenly her brain kicks back into gear – all too late, because when she snaps her mind back to the present, her head lifting up from her arm, she notices every pair of eyes in the room has turned to her intently. A prominent blush erupts across her cheeks.

"Miss Leonhardt," the instructor starts and she nearly punches Eren when he snorts gently into his fist, "are you feeling alright?"

"My stomach is killing me," she bluffs, such a bullshit lie she's sure not a single soul under this roof believes her.

"Do you need to be excused to the infirmary?"

Eren pulls out to stroke her again, slowly but still enough to help draw out her orgasm. This son of a bitch… She grasps the edge of the desk; then shakes her head. "N-no, the cramps are going. I should be okay."

After taking a moment to press his tongue to the inside of his cheek and glance her over with a scrutinizing gaze that briefly falls onto Eren, he quells the muffled laughter in the class with a quick "shush" and picks up immediately where he left off. A few eyes linger a bit too long on her for her comfort, namely Mina – who is seated beside Samuel in front of them – Reiner and Bertholdt, respective expressions ranging from quizzical to concern to amusement. She considers throwing her chair at Reiner. Or maybe she'll hand him his ass during their sparring session later.

They don't turn away for a solid minute, and she tries her damned hardest not to crumble under the weight of her embarrassment. "Annie," Mina whispers, leaning back against the wall of her friend's desk, "are you sure you're alright? You look a little red."

"Fine," she stresses.

Mina's lips shrink into a thin line, but she decides to let it be and returns her attention to the board. After his caresses draw to a stop, Eren gradually withdraws his hand from Annie's pants, resting it on his knee where it had started. "You're not very discreet," he muses, flinching in anticipation for a punch when she shoots him a menacing glare.

"You're an ass. You better make it up to me after class."

"But that's when we have Shadis' exam."

She glances at him out of the corner of her eye.

He grins, that trademark goofy, boyish, handsome smile of his. "Oh."

And they leave it at that.