So Dalton just sneezed in the kitchen. He doesn't hold back on his sneezes when he is at home and no one is right around him. It was a gross one. I gave him a tissue and then asked him if he had gotten boogers on my floor (not in the collection of questions I ever pictured myself asking another person). He said no, but took a step into the kitchen and very casually said, "Oh, yeah, I did" after which he proceeded to wipe the floor and the bottom of his foot without further comment.
I'm amazed at his lack of gross-out attitude, but should be used to it by now.