In the end, it doesn't matter how accurate it is - that he's doing enough to make Erwin feel good and not completely fucking it up is win enough, especially for his first time tasting another man's cock. It's maybe not as bad as he imagines, but perhaps that has more to do with wanting to do more for his endlessly patient husband. Levi knows the signs of his impending orgasm from a different angle, usually pressed close, listening intently to how his heart beats harder, his breaths come a little faster, the way he feels in his hand. That's about as far as they'd gotten sexually, until now. He's gotten more practiced at it by now, a little bolder, sometimes slipping his hand beneath Erwin's waistband as he recites in that low, velvet voice of his, enjoying the sensation of him stiffening slowly beneath his palm.

It seems they'll now have more activities to add to that small repertoire.

It is warning enough so that he doesn't end up with a mouthful of cum, but a spurt of it does land on his cheek, and more on his throat before Levi manages to direct Erwin's cock in a more benign direction, working him through the rest of it with his hand. It should outright disgust him, but instead there's a funny feeling that shudders through his nerves, making his shoulders twitch and his breath stutter.

Levi looks up from his place still on the shower floor, black hair wet and slicked to his skin, lips pink and plump from his work, eyes dark, staring. The splatter feels thick and sticky on his skin. The line of Erwin's body looming above, water tracing muscles and shifting with heavy breaths. Familiar scars crisscross his body, interrupting smooth planes, but Levi can't recall a time when he thought him anything but fucking gorgeous.

He licks his lips, the taste of Erwin still there. His brain stumbles a little, as he opens his mouth to make some comment about how he doesn't have to guess if Erwin liked what he got, but what comes out instead is:

"You're fucking beautiful."