In the Monster AU when Bucky first knotted Tony, Steve told him he was taking it better than he did, can we have a scene where Bucky knots Steve, or he tries but it doesn't work out so he ends knotting Tony again instead? I'm just in the mood for Bucky knotting one or both of his lovers ( ͡° ͜ʖ ͡°)
The problem with Steve isn’t that he can’t take a knot–it’s that he takes it too well. He’s always overwhelmed and sensitive. It wouldn’t be so bad except he’s so incredibly long and muscular that even what he considers “minor, overwhelmed twitching” is actually a pretty powerful writhe, and Bucky always has to scramble to stay on top of him because if he doesn’t, Steve could actually injure him. Intimately.
Steve is aware of this and is sort of depressed about it, because he loves being knotted. He’s just… also aware of why Bucky doesn’t do it often. So he absolutely loves it when Bucky goes into rut and can’t be sated with just one of them. It even tires him out enough that he can’t writhe as much! (Not that Bucky lets him, snarling, as he shoves Steve down with a hand around his throat so that he’s bearing his belly submissively, because Steve might be his mate but he’s also dangerous in his own right and Bucky needs a constant show of submission from him.)
As much time as Steve spends on his back during Bucky’s ruts, Tony spends on his knees. Tony already smells like Mate and Mine so Bucky doesn’t need to stake a new claim on him, and he’s so small and weak compared to him that he doesn’t need to see his belly or throat. Tony also whimpers and whines like he’s in heat every time Bucky fucks him so that’s just an added bonus. Steve loves being pinned down and knotted after they’ve both been exhausted–Tony’s arms gave out after the second time Bucky knotted him, and he’s so pretty like this, flushed face pressed into the sheets, ass propped up in the air, Bucky’s cum dripping out of his swollen hole and coating his thighs. His bitten-red lips are open, puffy with how often his teeth have dug into them, and his breath comes out in little wheezing hitches as he tries to catch it.
By the time Bucky finally exhausts himself, Steve can barely even move, he’s so well-fucked and sore. He feels tender with every twitch of his hips, and Bucky smugly shoves two fingers into him and fucks him with them, tugging at his tender scales until Steve fretfully whines. Just because Steve’s a monster, and tougher, doesn’t mean that he can take Bucky impatiently tugging his knot out before it’s shrunk down all the time. He considers himself lucky, though–Tony can’t even move, he’s so bloated and sore, and Steve winces when Bucky tugs Tony to fall onto his side and the human just lets out this small, pitiful noise as he goes.
“‘m so glad he only goes into rut every once in a while,” Tony whimpers as Steve helps him into the shower while Bucky sleeps off his hormone-crash. “Fuck. I think he bruised my insides.”
“I know he bruised my insides,” Steve mutters with a sympathetic wince.
Bucky is gentler on their human mate, but sometimes in the heat of the moment he forgets himself and shoves his knot in without as much care. Tony loves it in the moment, of course, but there’s only so many times it can happen on his delicate body.
Steve shudders as Tony flops onto his tail, unable to stand any longer, and can’t do much better. He coils around Tony as best he can, turns off the water until they catch their second winds to wash themselves, and turns on the heated tiles while he lies there so he doesn’t get too terribly cold as they wait.
(Bucky finds them passed out on the warm tiles and sighs fondly, instead running a bath for them. Tony whines when he feels Bucky scrubbing him down, trying to push him away, but then Bucky rinses him off and carries him out to set him in the tub, so… that’s okay, he guesses.
“Next time I’m gonna make you keep it in you,” Bucky threatens when Steve hisses and flashes his fangs at him when the lupine monster tries to scrub him.
Steve lets out a miserable little noise at the idea, because he feels bloated and sick already, and he’s already sore on top of that. He doesn’t know if he could even take a plug, he’s so sore.
“Into the tub you go,” Bucky cajoles gently, and Steve whines as he’s gently set into the tub, coiling quickly to pull as much of his tail into the tub as possible.
“Steve no,” Tony complains as Steve’s tail falls across him, keeping him pinned down.
“Steve yes, so he can ask me for help when he needs out,” Bucky replies immediately.)
((Bucky has stripped the bed and put clean sheets on it while they soak, and he takes time and care to help Steve coil up on it so he’s not too uncomfortable, and then helps drape Tony across his tail so he’s snuggled up against Steve’s chest.
“Still sore?” he asks gently.
“Tony, kick Bucky in the face,” Steve slurs.
Tony whines out a “can’t move my legs” before swiping weakly at Bucky’s face. Bucky swaddles them in blankets and swipes at their cheeks with his tongue apologetically before curling around them, now awake from the desire to protect his vulnerable mates.))
(((“Insatiable,” Bucky complains when Steve spreads himself out for him to knot again. He’s still got some hormones flushing through him though, so he’s really not that upset about it, even though he does have to be extra delicate with Tony when he fucks him next.)))
