The first time Bucky lies about his age, it's to get a date. Steve thinks he's being a dumbass, because while Bucky might be a smart fella six days a week, he's always had rocks for brains when it comes to pretty girls on Saturdays. She's got red lipstick and the kind of curves they've only see in the pictures; Steve knows right away that she's outta their league and way too mature for boys like them. Bucky asks her out anyway, and when he says he's sixteen instead of fourteen, she takes one look at the dirt stains on his knees and laughs.
Somehow Bucky still manages to take her to the movies, and Steve refuses to talk to him for a whole week.
The second time he lies about his age, it's to make the money stretch a little further between paydays. Steve had run out of asthma cigarettes and Bucky took his last dime to another borough's pharmacy and managed to sweet talk his way into a pack on account of 'only being thirteen and gee jolly his mama sure needed that medicine.' It wouldn't have worked in Red Hook, where everybody knows that Bucky's been fifteen since March, and even then Steve thinks it's quite the stretch. He won't ever be able to figure out how the pharmacist over in Prospect Heights could've bought that story now that Bucky's damn near six feet tall.
Third time Steve hears about Bucky lying about his age, he's telling a bartender in DUMBO that it's his eighteenth birthday, which is such a crock of shit that Steve almost ruins it by choking on his drink. Bucky glares at him but gets served a shot on the house anyway, probably because it's a queer bar and nobody cares that they're both too young to be there.
Fourth time it isn't so much a lie as an error on his enlistment papers. Steve glares at him for a solid thirty minutes when he sees it, and Bucky has the audacity to look him in the eye and promise to get it sorted out later, when he gets back. He never does.
"I am a hundred years old, and you can't be bothered to get an old man his sandwich," Bucky gripes from the sofa, metal arm thrown over the back and head tilted up to the ceiling as he loudly complains about this new injustice.
"You are not a hundred years old, you big fat liar," Steve snaps, pointedly taking a large bite out of his own sandwich on principle. He's never been Bucky's nursemaid before, and while he's glad to have his friend back, he's certainly not about to start now.
"I can't believe that you're so callous towards a decorated war veteran. The American people would be outraged! You're not a patriot, Steve; a true American hero would make his poor, decrepit old buddy a sandwich after he survived 70 years of torture."
Steve snorts, talking with his mouth full. "I can't believe you just played the 'tortured prisoner of war' card over a goddamn sandwich."
"My bones are ancient, Steve. I can't possibly be expected to hobble all the way to the kitchen and make my own," Bucky whines, but he's grinning. Steve swallows. "I got bad joints, you know. Workin' down at the docks all those years ago -"
"You were never a dock worker," Steve reminds him, but Bucky just keeps barreling on like he hadn't noticed the interruption.
"- and when Prohibition started -"
"You literally weren't born yet!" Steve yells in exasperation. Bucky just laughs, and it sounds so good - like it always does - that Steve can't even stay mad at him. He glares anyway, for appearance's sake.
"Promise me you'll never correct those historians for fuckin' up my birthday."
Steve sighs then and rips his sandwich in half to share. "You just like everyone thinkin' you're older than me, don't you?"
"More than you'll ever know, Stevie."