Midoriya knows Paul isn't actually being sick in the same way he knows that he, too, has something is stuck in his throat. It's less the part about washing hands, which he didn't mean, and more the part about making sure they've not got the--slippery stuff on them when they go downstairs, and the fact that he's clutching a well-wrapped vegetable. His previous absurd, untimely amusement at how stupid the eggplant looks escapes through his teeth in a shaking hiss like the delayed release of a broken dam.

The sudden flush of radish pink that colors his face is embarrassment--no, exasperation, as is the accompanying show of teeth--a grimace that immediately turns into a grin. He can think of only one correct response to what seems to be Paul's terrible rendition of how Kaworu insists on calling him by his given name.

He chucks the eggplant at Paul point blank and declares, "You're not ruining eggs for me too!"