This actually makes Keita stop for a second, because he'd absolutely just assumed he should be the middle part of the sandwich. But then he remembers Yukimura's answer to his question.

The crawling continues, now over Yukimura to his other side, where Keita settles and hugs around his middle. His arms don't reach very far.

"Yukimura-san can be the middle. Because he dreamed bad too."