Shiro's laughter dies down, eventually, but he's still amused, he's still grinning. He's just going to casually finish up his own food, and move to start cleaning up his own dishes.

Listen, he's hopeless in the cooking department. But he can do the cleaning.

So when Ritsuka offers to do it, he just shoots him a smile - another one. This one meant to be reassuring.

"Hey, you did all the work with the food, I can clean up, no problem."