tonystarktogo:

Headcanons focusing on the delightful Protective!Winter Soldier and kid!Tony/deaged!Tony dynamic that needs to be written way more often. You’re welcome.

• tiny!Tony being absolutely fascinated with the metal arm and treating it like his favourite stuffed animal, always cuddling with it when he needs comfort, petting it, talking with it and insisting it gets goodnight kisses. tiny!Tony’s the only one allowed to touch it because he has The Pout and Bucky never stood a chance. (Seeing an adorable, small child showering his arm with love may or may not help Bucky accept the metal arm as something more than a killer tool HYDRA bestowed on him.)
• tiny!Tony shocking everyone when he twists his attackers’ right hand to get out of their hold. tiny!Tony then promptly turning around and breaking their left one as well, causing Captain America to ask with a disapproving look if that was really necessary. tiny!Tony not being impressed at all because “everyone is ambidextrous until proven otherwise, don’t you know that?”. (The Winter Soldier standing right behind tiny!Tony, puffed up like the world’s proudest mom because that’s his boy.) (Steve pinching the bridge of his nose in annoyance because no, Clint, leaving an impressionable Tony with a brainwashed assassin does not count as adult supervision.)
• A concerned Pepper taking tiny!Tony aside and explaining how it’s important for people’s mental health and development to have friends their own ages. tiny!Tony taking her very seriously while simultaneously missing the point completely and immediately setting up playdates for the Winter Soldier at a local retirement home.
• tiny!Tony being banned from the coms during Avenger missions (he watches them fight safely from inside the Tower of course) because whenever he becomes excited about a trick one of them performs the Winter Soldier gets jealous and pulls an even more showy/dangerous/impressive/reckless move. Nobody is allowed to be tiny!Tony’s Most Awesome Person Ever except for him.
• tiny!Tony discovering through a gossip magazine that he and Pepper used to be a thing, plus speculation that they’re secretly planning their runaway wedding. tiny!Tony consequently inviting Pepper over and sitting her down to explain in a very grave voice that she’s really pretty and her high heels are scary and she’s awesome with a nerf gun but he can’t marry her despite all that because married people share everything and he won’t share his Bucky. (On a completely unrelated note Steve finds himself locked out of Bucky’s room and on a more memorable occasion the entire Tower with alarming regularity.) 
• The team taking their responsibility of caring for tiny!Tony very seriously, including: Bruce child-proofing and Tony-proofing the kitchen, the living quarters and bedrooms, Natasha reading parenting books and traumatising the SHIELD junior agents while she is at it, Sam buying child (genius) appropriate movies, games and toys and Steve working with Pepper on schemes to keep the public from finding out what’s happened. Meanwhile Tony and his assassin babysitter proceeding to start the Most Epic Very Explosive Possibly Last Ever experiment in Tony’s workshop that everyone just assumed JARVIS would put into lockdown…
• Steve and Sam taking the Winter Soldier (who still has trouble understanding social norms, cues and interactions) aside to delicately explain that tiny!Tony is not to be treated like adult!Tony and how it’s important to account for this difference at all times. The Winter Soldier signalling his understanding and acceptance of the newly adjusted mission parameters, then proceeding to drag a curious tiny!Tony to the armoury to familiarise himself with any and all weapons he can efficiently use with his current size and weight.
• The Winter Soldier is on babysitter duty, and he knows – Captain Rogers explained it five times – that it’s important for tiny!Tony to tire himself out before bedtime. The Winter Soldier does the obvious, age appropriate thing: he puts tiny!Tony through the average Red Room trainee routine every evening for a couple of hours. Several weeks go by and suddenly the Avengers have to deal with a tiny!Tony ninja. The team is not impressed.
• Bucky and tiny!Tony being alone at the Tower when something triggers the Winter Soldier. tiny!Tony being completely unaware, not even noticing the change. tiny!Tony taking everything the Winter Soldier does as a game or a joke. Or maybe he thinks this is another one of those In Case You Get Kidnapped training simulations a certain paranoid Bucky has been known to put him through.