It's less laughing at him, and being more amused to see nothing's changed. Of course not, since Steve is, technically, still himself. It's just weird to think about, when you grow up with the mythos of this supersoldier, and a couple months companionship doesn't really change it all. Even if it does mean Clint has a better grasp on who Steve is, what he's like. He likes the guy, but he doesn't much know him.

That said, it is very obvious that Steve doesn't want company. But here's the thing, Clint's just as stubborn as Steve is, and he also happens to be partners with a stubborn son of a gun too. Also, he's still unsure around a certain ex-brainwashed Russian assassin and he tends not to get on their bad sides if he can help it. Sorry, Steve.

"Ouch," Clint does actually laugh at that, faintly delighted, an easy sort of thing. Luckily for Steve, the sound of his shoulder popping is faint enough that Clint doesn't hear it, though he does see the faint tightness written in Steve's expression.