I have this weird moment on my harddrive, where Steve keeps seeing Natasha and Tony flirting with one another (and Tony is always giving her gifts, often fancy and/or expensive because he doesn't think about the cost of things being an issue, and Natasha is one of the best people he's ever met about receiving gifts) - it's completely not a thing between them, because T & N know they'd tear each other up (their other relationships aside) if they ever went there. They know they're *too* alike, you know?)

But they flirt, and they bicker, and he gives her gifts, and Steve gets worried and tries to take Clint out for beers to talk about it, and Clint nearly spits his beer out all over the table because he's laughing so hard when he figures out what Steve's worried about.

Because my headcanon Clint is like the least jealous person on the planet.