Thread by @Iracebeth3

cw// nsfw, poly relationship, underage

The one awful thing about fucking Fatgum is that you can't bite him.

It kind of sucks, but it's true: whenever Tamaki tries to give him a bite, his teeth sink in his fat, like pretty much any other sharp object. Even when he tries with+

all his might, he can't. And it drives him absolutely insane.

Kirishima and Tetsu say they don't mind it, but Tamaki can hardly measure himself with them: they haven't been here as long as he has. They haven't gone through the frustration, the /helplessness/ of wanting to mark+

him, just a little, and finding it impossible.

It's silly. Tamaki doesn't own Fat: no one can, and it's not like any of them /want to/. /Especially/ not Tamaki, with Mirio, and their entangle of a relationship where he can't tell where one finishes and the other ends.

He doesn't want to own Fat. He doesn't mind other people having him: Kirishima, and Tetsu and Mirko and that brawler guy that comes once a month looking for a fight. He's seen Fat after every time — how good he looks and feels. And he wouldn't trade that for the whole world.

But.

But maybe Tamaki is just not as good as them — maybe he's just selfish. More selfish; more insecure.

Everyone else is so good; arguably better. Maybe he just wants to leave his mark on him. Because maybe he's the least of all of Fat's partners, and he needs+

something (anything) to remind himself he was there. That he had him, even for just a minute.

So when Fat has to release all his fat in a punch during a mission, Tamaki takes his chance.

Even before police has finished clearing out the area, he's dragging his mentor out of+

the scene.

Fat protests. Out of all his partners, he's the least sympathetic of Tamaki's anxiety, and he's never stopped himself from scolding Tamaki for running away from a scene before the cameras roll by. He's about to tell Tamaki to man up, probably, when Suneater stops+

dead in his tracks to run a slow, suggestive hand up Fat's wrist.

/Later/.

Fat's cock twitches. He swallows hard and lets Tamaki lead him back to the agency.

It's a blur after that, crossing the door and undressing. Fat's hands on his hips as he kisses him. It's slow and soft and tender-

And then Tamaki's teeth sink on his bottom lip; sharp fangs making him moan. Fat squeezes the boy's hips and carries him to a couch — the+

nearest horizontal surface. He unclasps the vest and throws it, while Tamaki gets rid of his hoodie and tank top.

The first bite comes right at his neck, while he tries (and fails) to get Tamaki rid of his bodysuit. The feeling is unusual — intense. Fat can't remember the+

last time anyone bit him that hard; let alone the last time he felt it.

Tamaki doesn't stop. He sinks his teeth deeper and sucks, until Fat's hands open, his cock twitching in his pants.

Fat wants to say something, but Tamaki's teeth sink in his shoulder and his breath gets+

caught in his throat.

It doesn't stop. Tamaki bites harder, deeper, until Fat can't remember his own name, or coordinate what to do with his hands. Next thing he knows he's gripping at the boy's hair, moaning as he bites his nipples, as his tongue snakes his way lower, and+

lower, untill he's sinking his teeth on his hipbone.

Toyomitsu doesn't know how he ended up sitting on the couch, with Tamaki kneeling between his spread legs and sucking and biting on his thighs.

Tamaki looks so good like this — his hair messed up and his lips red and+

swollen. Fatgum wants to push his dick past those lips — come down that deliciously tight throat. It's always a treat to get head, but there's little hotter for him than seeing Tamaki swallow. There's something oddly hot about it: no matter how much he comes or what+

he does, Suneater always (/always/) swallows.

But- considering Tamaki is having a /teeth/ day- maybe not today.

Before Tamaki can get him into his mouth, Fat picks him up from the floor. He feels huge, still — his hands massive on Tamaki's slender hips as he moves him+

around, placing him on the couch.

Normally, Fat would take his time — tease Tamaki out of every layer of his hero costume. But he's hard and hot, and can see Tamaki is, too, just from the look on his face.

Instead of bothering with his costume's skirt, Fatgum rips off his bodysuit. Tamaki's cock twitches, finally free, exactly half a second before Fatgum's huge (always so /so/ big) fingers prode his asshole.

No matter how desperate he is, Fatgum always takes his time to do this — he cannot risk hurting Tamaki. It seems like a kind of sweet torture — thick fingers opening him up so slowly, when the only thing he wants is to be wrecked.

This time, however, he doesn't lay down to take it. He sits up to bite Fatgum's neck — sink his teeth on the skin and suck, until his fangs find bone.

Tamaki can't tell whether Fatgum speeds up the prep or he feels it's shorter because he has something to do. But soon+

enough that cock is ripping him open, filling him up to the brim. He screams as Fat fucks into him, so quick and hard he can't think of anything but /good/ and /more/ and /please/- he can't bite. He can only dig his nails in Fat's back, desperate to leave his mark.

He can feel when Fat is about to come — the movement is only half-thrusting, half using Tamaki like a fleshlight. He comes inside and /fills/ him, so full Tamaki comes too, so hard everything goes white.

It's always quiet afterwards. The air around them is warm and heavy and thick, but it's not unpleasant. Fat's fingers make circles on Tamaki's hips, trying to help him relax. Tamaki pulls back to thank him (for taking him in? For fucking him? For existing?) he catches+

his first good look of Fat.

His shoulders are covered in bite marks; his neck circled by a beaded collar of purple hickeys and red bites. The trail is vicious against Fat's unblemished skin; little signs of Tamaki's teeth and mouth painted all over his skin.

It screams property. /Mine/. It's ridiculous. Maybe childish.

He loves it.

"What're you smiling about?"

Fat seems- confused, but not upset. Tamaki knows that won't change — he won't mind Tamaki using him as a chewing toy. At the end of the day, he just wants him to be+

happy. Even if Tamaki is illogical, and petty, and not quite as good as everyone else.

His smile is still right in place when he answers.

"These look good on you," he whispers, right before dropping a kiss to one of the marks on Fat's shoulder.

Fat's reply? A booming burst+

of laughter, right before dropping a kiss on Tamaki's hair.

"Thank you, then."

(~end)

This doubles up as a little treat for Fatgum's birthday and a very late little something for @notrishno's birthday o/

Hope you like it! x'D