"Too hard...?" Unable or unwilling to eat... Just another sign how very, very out of sorts his brother is. And there's a joke to be made here, about not eating and wasting away to bones, but... Papyrus isn't the skeleton to make it. Maybe later, once this is distant enough they can laugh. Maybe never, it's not that good a joke.

At least he's responding to the notion of food, and eating it, like he knows what that is. And with a little less unhappy helplessness.

"Hmmm. Is that because, you think you'll get sick?" If so, he's going to enlist advice from people with stomachs before offering more than a couple bites. Getting vomited on... for the sake of family or friends, he'd bear it if he must, but he'd really rather not.

"Or because your hands are tucked away, and you're not sure how to feed yourself? You might manage with your tail." And if not, well, he probably won't think to handle the door handle that way. "If not... I am here, and ready and able to help in the ways that I can."