In 1976 James Buchanan Barnes (in Winter Soldier look and mood) is assigned as bodyguard for a 6-year-old Tony Stark. Bucky is grumpy as fck but Tony is happy about his new buddy - he is super cute towards him, always smiles and is excited because his parents always ignore him (Maria and Howard have no time, jobs are too intense, you decide). Bucky makes slow friends with his babysitting life, but likes to be there for Tony even if he doesn't want to admit it.
Of course, there are not only good times. Bucky also sees how things are going at the House Stark and Tony is neglected or poorly treated by his parents. Bucky intervenes to protect Tony, but submits to Howard's arguments not to be dismissed.
Here's a list of babysitter Bucky's responsibilities:
play,
cooking,
bathe (imagine Anthony Edward Stark, covered only in bath foam, giggling in front of a completely overstrained Winter Soldier dashing through the house),
put him to bed (of course also includes reading good night stories and imitating matching voices from the book),
keep Tony safe from Hydra and other bad guys,
take him to school and pick him up again,
help with schoolwork,
activities such as going to the zoo,
go shopping, even toys.
I have this headcanon that Bucky can sing and come up with new songs especially for Tony to calm him down or use as a lullaby.
Lots of hugs and fore head kisses bc Bucky cares.
And Tony is also interested in Bucky's metal arm, but Bucky never tells the story. Instead, he lets Tony put on colorful magnets or stickers. And yes, we need that part in this fic (:
I would be happy if someone would like to write a ff or use parts of it. But please give credits ^__^