Kate bites back a smirk at that and just pats his arm instead. She's being a smartass but she doesn't need to be noisy about it. Kate's got a great pokerface, but Steve doesn't even need one he keeps his emotions pushed so far down.

Instead of busting his balls about it, she sighs a little after and asks, "Do you think it would work at home, you and him, or is it just the island?" and it's probably clear she's not just talking about them.