I was talking to reclusiveq and ended up sending her several askbox ficlets/headcanons (on tumblr). As I pictured them all occurring in the same storyverse, I figured I may as well post to AO3 for others to read. And if you like Stucky, or Sebastian Stan in general, you should probably follow her blog (I do).
Originally post 2014-09-27 to AO3 and forgot to post here.
Bucky gets his mechanical arm stuck in a vending machine and he can't pull it out because the metal flaps on his arm keep getting stuck. So he rips it out, but the front of the machine comes with him, and the machine topples over. He's still stuck under it when Steve walks in and Steve laughs so hard he can't stand. Bucky is so mad he won't look at him even when Steve crawls over and kisses his face (still laughing), so Steve keeps going until Bucky relaxes enough to get unstuck.
.oOo.
Bucky's metal arm is so heavy that he can't swim. The first time Steve goes to the pool, he convinces Bucky to get in by giving him several of inflatable water wings, all of which go on his metal arm. Steve lures him into the water with Marco Polo, almost drowning because he can't handle how adorable it is to see the infamous assassin with an entire arm of water wings. Bucky vows to never swim again, but every time Steve takes his shirt off to get in, he forgets his vow and follows.
.oOo.
Steve never really cared for food in bed, until the first time Bucky asked to try chocolate syrup and whipped cream. The resultant mess got inside every one of Bucky's lower metal plates, and sent the man into a tantrum. Steve can't stop smiling though at the way Bucky lets him care for him in the shower, lets him caress and clean between each plate, and it tended to end up with a more cleanly session in bed. But as much as Bucky hates it, the next time Steve asks, he complies without question.
.oOo.
"Tag." Bucky barely has time to process the tap to his shoulder before Steve is racing away. After a moment, it registers that his prey is getting away and he bolts to follow. Steve leads him on a mad chase through Stark tower, down hallways, through rooms, and up staircases, his familiarity with the complex an annoying advantage. But finally, Steve is trapped on the roof and Bucky tackles him. Steve laughs as he hits the ground, and Bucky growls as he captures the gasping lips in his.
.oOo.
When Bucky moves into Steve's room at the tower, for a long time, he doesn't sleep. At least, not when Steve does. He stand guard over Steve's door, knife in hand. Slowly, Steve coaxes him into laying him on the bed, though he posture is always stiff and the knife doesn't leave his hand. It's weeks before he keeps the knife sheathed when Steve goes to sleep, weeks longer still before he falls asleep with Steve curled around him.
FIN
Somehow I've only really written G-rated Stucky so far. One of these days I'll actually get around to writing E-rated Stucky. Hope you enjoyed, don't forget to review, and don't forget to come by my author tumblr (themadkatter13-fanfiction) to say hi!