Prompt: Best Friend's Sibling

—§§§—

So it goes like this:

James Rhodes and Sam Wilson have been best friends since Sam pushed him over in the sandbox in preschool and then helped him back up when he started crying. Sam has been friends with Steve since they met freshman year of high school in ROTC. Steve is best friends—by which James means attached at the freaking hip—with James Barnes, who luckily has already been going by Bucky for years, so there's little to no name confusion. Sam is fine with sharing best friend status among them like a community cash pot.

And Bucky and James get along, if not like a house on fire, than at least like a gently smoldering motel. So when Sam and Steve are being responsible and doing their English essays on a Friday night, Bucky calls James instead.

"It okay if I bring my little brother?" Bucky asks James with a bit of a grimace, like he already knows how that sounds. "I mean, he's cool. It'd be cool. But I won't if you'd rather I didn't."

James frowns. "I didn't know you have a brother."

"Step brother," Bucky explains. "I mean, he's our age. I just call him little to mess with him, 'cause he's short. He just spends way too much time building nerdy stuff in his room, so I thought, maybe he'd actually finally make a friend—" He stops and winces, then clears his throat. "Forget I said that. Little bro or no?"

"Sure," James says, because the caring-older-brother side of Bucky is one that James hasn't seen since Steve actually started winning his own fights. Besides, this kid sounds lonely.

And that's how James meets Tony Stark.

—§§§—

If James thought Tony must be lonely, the kid probably does it to himself. He has two modes: doesn't shut up and doesn't pay attention, and they have a frustrating habit of overlapping.

When Tony jumps in the car, he gives James a once over, looks at Bucky, and says, "Who's this? Your boyfriend?"

Bucky's hands tighten slightly on the steering wheel and James wonders if Tony actually knows that Bucky's gay, or if he's just being a jerk. Bucky takes a breath. "No. This is James."

"No, you're James," Tony frowns.

Rolling his eyes, Bucky looks over his shoulder at him. "I'm Bucky, he's James. What's your problem?"

Tony huffs an indignant little sigh and looks to James instead. "James…" He rolls his hand in an expectant gesture.

Bucky says "Just James" at the same time that James says "Rhodes."

"Rhodey it is," Tony decides, nodding regally.

Bucky shoots James a look that says I'm sorry, but James just shrugs good-naturedly. He can deal with a nickname for one night.

—§§§—

It isn't just one night. Maybe they shouldn't be friends, but somehow they are. James meets Pepper, Tony's long-distance ex (like a long-distance girlfriend, Tony says, except apparently there was a thing and she's dating someone else but is somehow awesome enough for Tony to still hang onto) and somehow accidentally builds a robot that sets off the fire alarm at the school. Twice.

So they've only known each other for about three months and James is already cursing himself for ever meeting this kid, not because of getting grounded or almost getting caught for the fire alarm thing, but because Tony charms the pants off of everyone he meets and, judging from his string of popular exes and fan club, is one hundred percent heterosexual.

But apparently James is a masochist, so he hangs around Tony anyway.

"You know," Tony says, and they've been friends for three months and a week. They're on the lawn in front of Bucky's house—Tony's too, James supposes—and James is sprawled out on his back while Tony picks at the grass. "If you are Bucky's boyfriend, I don't really care. I know he's gay, even if Dad doesn't. I won't tell anyone."

"I am aware of Bucky's sexuality," James says levelly, staring at the clouds, "but no, I'm not his boyfriend."

"Oh." Tony picks a dandelion and pulls all the little yellow pedals out. The wind blows a few onto James' face when Tony lets go. "Oh," he says again, a little panicked, "are you straight? I didn't mean to assume. Just, Sam and Steve, I figured his gaydar was a gay magnet too—"

"I'm gay," James says, cutting off Tony's motor mouth before he says anything else embarrassing or vaguely incriminating. Sam and Steve—have those two finally got their shit together?

"Alright." Tony seems vaguely smug, which annoys James probably more than it should. "Do you think I'm hot?"

James sits up fast and glares at Tony. "Just because I'm gay doesn't mean I want to make out with every boy I see."

Tony blinks and cautiously puts his hands up. His fingertips are stained green. "Sheesh, I know. I mean, nobody could find Justin Hammer hot. I just wondered."

James looks away from Tony's face and down at the grass. It'd been so comfy just a moment ago, but the lazy, content mood has dissipated and he's left feeling awkward and out of place. "Why do you care, anyway?"

"Um, 'cause I'd kinda like to make out with you?" Tony says. "But, I mean, if you don't want to then that gets a little difficult." James slowly looks up to stare at him. Tony blinks at the sudden focus: "What?"

"But… you're straight."

"Bi, actually," Tony shrugs. Then frowns. "You really thought I was straight?"

James doesn't answer because it's just processed that Tony wants to kiss him. So he does the only reasonable thing and grabs Tony's shirt, pulls him forward and kisses him right on the mouth.

It's understandable that they don't hear the car pull up, since they're so busy making out on the lawn. But it's kind of hard to ignore Bucky's flabbergasted "What are you two doing!?"

Neither of them are sorry.