Oh, he understands perfectly. He just chooses not to acknowledge that she might have a point. Just because he wouldn't like it if he were the smaller one doesn't change the fact that they're all going to be the same person again eventually, and until then he can do what he pleases to himself. He's the biggest, after all. Tough luck to the smaller one.

"Aha!" the smaller Andrew seems to have found what he was looking for. If Daine were to put her paws up there, she would see that the clattering sound that results is him pushing buttons on a typewriter, one at a time, throwing his whole weight into it. After a few moments, he calls down, "Door on the left, then right, then right again, right down the stairs, left at the third fork, first door on the right. Could've put it a bit closer, old girl...."

"Never mind," says the Andrew below, waving it off. "We'll manage. Come on, Daine, you heard him."

And he turns toward the door, ready to walk off and leave the other Andrew stranded without even thinking about it.