Dean swallowed the mouthful he had, then looked around blankly, wishing he could actually hold a decent conversation with Sam. Of course, this gave him the chance to say thanks without having to hear the other side of it all.
"Hey, Sammy, uh... thanks, for all this. You know, crap you shouldn't have to do for me." After all, he was being helped with bathroom stuff, being fed, having help being dressed. It was a lot to ask.